BIOLOGY 
J.U3RARV    / 


THE  MECHANISM  OF  THE  BRAIN 

AND    THE 

FUNCTION  OF  THE  FRONTAL  LOBES 


THE  MECHANISM 
OF    THE    BRAIN 

AND    THE 

FUNCTION  OF  THE 
FRONTAL    LOBES 

BY 

PROFESSOR  LEONARDO   BIANCHI 

Senator  of  the  Kingdom  of  Italy,  Professor  of  Psychiatry  and  Neuropathology 
in  the  Royal   University  of  Naples,  Ex-Minister  of  PuNic 
Instruction,  Honorary  Member  of  the  Medico- 
Psychological  Association  of  Great 
Britain  and  Ireland, 
etc.,  etc. 

AUTHORISED  TRANSLATION  FROM  THE  ITALIAN 

BY 

JAMES   H.  MACDONALD 

M.B.,  CH.B.,  F.R.F.P.S.(GLASG-) 

MacKintosh  Lecturer  in  Psychological  Medicine,  Glasgow  University  ; 

Medical  Superintendent,  Govan  District  Asylum, 

Haivkhead,  Glasgow 

WITH   A   FOREWORD   BY 
C.   LLOYD   MORGAN,  L.L.D.,  D.Sc.,  F.R.S. 

Emeritus  Professor  in  the  University  of  Bristol 


EDINBURGH 

E.    &    S.    LIVINGSTONE 

1922 


BIOLOGY; 
RA 
G 


PRINTED    IN    GREAT    BRITAIN 

BY   THE   RIVERSIDE   PRESS   LIMITED 

EDINBURGH 


AUTHOR'S  PREFACE 

THIS  volume,  which  I  now  offer  to  physicians  and  others  interested  in 
the  study  of  cerebral  functioning,  is  the  outcome  of  a  series  of  experi- 
mental investigations  expressly  undertaken  and  covering  a  considerable 
period  of  time,  commencing  with  the  year  1888.  Indeed,  from  the  time 
I  first  applied  my  mind  to  the  problem  of  functional  localisations  in  the 
cerebral  cortex,1  I  had  become  convinced  of  the  need  for  this  special 
research. 

In  1881  I  had  occasion  to  observe  a  remarkable  feature  relating  to 
dogs  which  had  undergone  extirpation  of  the  sigmoid  gyrus  of  both  sides. 
I  was  struck  by  the  fact  that  there  was  an  appreciable  difference  in 
behaviour  between  those  animals  in  which  the  extirpation  had  been 
limited  chiefly  to  the  sigmoid  gyrus,  affecting  either  the  whole  or  a  part 
of  that  convolution,  and  other  animals  in  which  the  operation  had 
involved  more  than  the  sigmoid  gyrus,  having  extended  forwards,  in 
front  of  the  presylvian  fissure.  I  had  performed  these  operations  with 
the  special  object  of  elucidating,  as  far  as  possible,  the  problem  of 
functional  compensations  within  the  cerebrum  and  the  anatomical  limits 
within  which  cortical  compensation  was  possible.  The  experiments  had 
perforce  to  be  numerous,  and  it  was  also  necessary  that  I  should  keep 
the  animals  under  observation  for  a  long  time  after  the  operations. 
Thus  it  came  about,  apart  from  any  stimulus  to  further  investigation 
to  be  found  in  the  scanty  literature  of  the  subject,  that  there  arose  in 
my  mind  a  strong  desire  to  attack  the  problem  of  the  function  of  all 
that  cerebral  area  which  is  situated  in  front  of  the  presylvian  fissure, 
a  function  that  was  wrapped  in  utter  darkness.  Afterwards  came  the 
great  discussion  between  Hitzig,  Munk,  and  Goltz,  and  thenceforwards 
I  applied  myself  seriously  to  this  particular  inquiry. 

During  the  session  of  the  International  Congress,  in  Rome,  in  1894, 
a  committee,  composed  of  eminent  authorities,  including  amongst  others 

1  L.  Bianchi.  (<  Sui  centri  motor!  del  cervello."  Communication  to  the  Assocla- 
zione  del  Naturalisti  e  Medici,  21st  February  1878. 

"  Sul  significato  della  eccitazione  della  zona  motrice."  Movimento  Medico 
Chirurg.  Anno  xii.  1880. 

"  Sulle  compensazioni  funzionali  della  corteccia  del  cervello."  La  Psichiatria,  la 
Neuropatologia  e  scienze  affini.  Naples,  1883  ;  and  Rivista  Sperimentale  di  Freniatria. 
1882. 

"  Ancora  sulla  dottrina  dei  centri  corticali  motori  del  cervello."  La  Psichiatria, 
etc.  1885. 

"  Le  degenerazioni  sperimentali  nel  cervello  e  nel  midollo  spinale."  In  col- 
laboration with  Professor  D'Abundo.  La  Psichiatria,  etc.,  1886,  and  N eurologisches 
Centralblatt,  1886. 

5 

4794 i- 


6  AUTHOR'S  PREFACE 

two  highly  esteemed  friends,  the  late  Professor  Hitzig  and  Professor 
Henschen  of  Stockholm,  was  appointed  for  the  special  purpose  of 
examining,  and  reporting  upon,  the  monkeys  I  had  operated  upon,  and 
still  retained  under  observation.  Although  the  judgment  pronounced 
was  distinctly  favourable  it  was  at  the  same  time  hedged  around  by 
many  reservations.  The  conclusions  I  had  outlined  were  afterwards 
subjected  to  criticisms  by  a  number  of  physiologists  in  Italy  and  else- 
where, criticisms  that  were  not  always  dispassionate  and  unprejudiced. 
The  arguments  adduced  by  these  opponents,  however,  were  never 
cogent  enough  to  overwhelm  me.  Additional  experiments  and  new 
methods  only  served  to  deepen  my  conviction  of  a  physiological  reality 
that  withstood  all  the  weightiest  and  best  directed  attacks.  My 
subsequent  communication  to  the  Congress  at  Madrid  had  this  result, 
that  it  opened  up  more  practical  paths  for  the  investigation  of  the 
functions  of  the  frontal  lobes.  Later  on,  the  rigidly  conducted  investi- 
gations of  two  distinguished  physiologists,  Shepherd  and  Bechterew, 
giving  results  that  were  uniform  with  those  obtained  by  me  in  a  new  and 
contemporary  series  of  experiments,  convinced  me  that  the  time  had 
now  arrived  when  I  might  opportunely  publish  the  synthetic  results  of 
all  my  experiments,  along  with  the  conclusions  that  had  been  maturing 
in  my  mind.  ^ 

My  first  intention  was  to  publish  a  work  that  would  appeal  only  to 
medical  men,  and  with  that  object  in  view  I  had  collected  a  number 
of  clinical  cases.  On  continuing  my  inquiries  and  subjecting  the  pub- 
lished clinical  observations  to  close  examination,  it  became  clear  that 
a  considerable  number,  if  not  indeed  the  majority,  of  these  could  not 
be  utilised,  for  many  cases  had  been  recorded  both  for  and  against  the 
doctrine  of  the  high,  psychic  function  of  the  frontal  lobes  which,  in 
their  ultimate  analysis,  were  destitute  of  any  real  value.  I  therefore 
abandoned  the  idea  of  dealing  with  the  clinical  aspects  of  the  subject  in 
this  volume.  With  the  outbreak  of  the  Great  War  I  could  foresee  that 
a  rich  store  of  human  material  would  become  available  for  the  advance- 
ment of  the  physiology  and  pathology  of  the  brain,  and  I  therefore 
.decided  to  put  into  print  only  the  present  volume,  devoted  to  general 
doctrines,  to  the  experimental  aspects  of  the  subject  and  to  an  initial 
phase  of  anatomical  psychology,  postponing  the  analysis  of  clinical  cases 
to  a  more  opportune  time. 

I  have  thought  it  particularly  important  to  set  forth  clearly  the 
outstanding  points  in  the  physiology  of  the  cerebral  mantle,  to  review 
the  doctrine  of  the  localisations,  which  appeared  for  a  time  to  have  been 
rudely  shaken  by  the  views  expressed  by  Loeb  1  and  Monakow,2  and  to 
define  as  clearly  as  possible  the  functional  relations  between  the  cerebral 
mantle,  properly  so-called,  the  zone  of  language,  and  the  frontal  lobes. 
I  have  also  considered  it  necessary  to  lay  down  certain  rules  which  may 

1  Loeb.     Report  of  the  Congress  of  Geneva.     1909. 

2  Monakow.     Les  localisations  cerdbrales.     Wiesbaden,  1914. 


AUTHOR'S   PREFACE  7 

serve  as  reliable  and  useful  guides  to  clinical  investigations,  and  so 
counteract  the  tendency  to  encumber  the  clinical  literature  of  the 
subject  with  superficial  observations  and  with  conclusions  that  are  too 
often  one-sided  and  hasty,  and,  consequently,  of  little  or  no  real  value 
for  the  progress  of  science,  more  especially  of  anatomical  psychology. 

If  it  be  claimed  for  psychology,  now  so  full  of  nattering  promise  and 
suggestion,  that  it  is  well  that  it  be  not  restricted  to  one  sole  path  of 
progress,  and  that  it  may  even  be  permitted  to  indulge  occasionally  in 
a  new  form  of  transcendentalism,  ingenious  and  fantastical  though  that 
be,  it  nevertheless  remains  the  constant  duty  of  the  biologist  to  safe- 
guard the  one  sure  pillar  to  which  it  may  be  fastened,  like  a  ship  to  its 
moorings. 

Human  and  comparative  anatomy  and  histology,  comparative 
psychology,  experiments  upon  the  brains  of  the  more  highly  developed 
mammals,  aided  by  psychological  and  anatomo-pathological  research, 
and  the  pathology  (including  psycho- pathology)  of  the  human  brain, 
are  the  most  reliable,  if  not  the  only,  fields  of  study  which  provide  us 
with  facts  of  a  positive  character,  fields  which  can  be  made  to  yield  a 
rich  harvest  to  psychology,  which  to-day  dominates  the  modern  spirit 
of  inquiry. 

Such  are  the  criteria  which  have  inspired  the  work  summarised  in 
the  present  volume. 

L.  BIANCHI. 


TRANSLATOR'S  NOTE 

WHEN  I  had  completed  the  translation  of  Professor  Bianchi's  Traltatto  di 
Psichiatria  I  did  not  anticipate  that  I  should  again  undertake  a  similar  task. 
The  translation  of  a  scientific  work  entails  much  careful  thinking  and  pains- 
taking labour,  if  it  is  to  be  presented  in  language  which  is  intelligible,  precise 
and,  at  the  same  time,  a  faithful  interpretation  of  the  author's  thoughts. 
Nevertheless,  I  have  experienced  a  sincere  pleasure  in  the  translation  of  this 
latest  work  of  Professor  Bianchi,  because  I  am  convinced  that  it  has  come 
at  an  opportune  time  and  that,  notwithstanding  the  enormous  increase  of 
psychological  literature  in  recent  years,  there  is  ample  room  for  another  work 
which  will  enable  us  to  develop  our  notions  of  the  relations  that  exist  between 
mind  and  brain,  without  transgressing  biological  limits. 

The  great  impulse  which  has  been  imparted  to  the  study  of  psychology 
and  psychological  problems  in  recent  years  is  due,  in  part,  to  the  influence  of 
the  leaders  of  psycho-analytical  schools  of  thought,  but  it  is  also  the  inevit- 
able result  of  modern  discoveries  in  the  realm  of  physical  science.  The 
psychologist  is  indebted  to  the  physicist  for  those  facts  he  has  brought  to 
light  which  go  far  to  prove  the  inseparability,  the  oneness,  the  continuity  of 
matter  and  force.  From  these  later  conquests  of  physical  science  the 
psychologist  will  draw  inspiration  which  will  help  him  to  confront,  with 
renewed  energy,  the  obscure  problems  of  psychic  life. 

To  the  masters  of  psycho-analytical  research  we  are  indebted  for  much, 
and  not  least  for  the  enthusiasm  they  have  awakened  in  many  new  quarters 
in  the  pursuit  of  psychological  studies.  It  is  true,  however,  that  not  a  few 
of  the  many  who  have  come  forward  as  exponents  of  the  new  psychology 
have  failed  to  give  evidence  of  that  length  and  breadth  of  experience  which 
would  entitle  them  to  be  ranked  with  the  authorities.  That  cannot  be  said 
of  the  author  of  this  work.  The  doctrine  of  the  higher  functions  of  the  frontal 
lobes  herein  advanced  is  the  outcome  of  many  years  of  study  and  research 
on  the  part  of  one  whose  long  record  of  scientific  activity  and  achievement 
must  claim  our  admiration  and  respect. 

I  sincerely  hope  that  the  author  may  not  have  to  say  of  the  translator : 
"  Traduttore—Tmditore." 

To  my  colleague,  Dr  D.  McKinlay  Reid,  I  am  indebted  for  much  valuable 
assistance  in  the  revision  of  manuscript  and  in  the  correction  of  proofs. 

JAMES  H.  MACDONALD. 

GLASGOW  UNIVERSITY, 
15th  February  1922. 


FOREWORD 

By  C.  LLOYD  MORGAN,  LL.D.,  D.Sc.,  F.R.S. 

Emeritus  Professor  in  the  University  of  Bristol 

PROFESSOR  BIANCHI  is  a  stalwart  champion  of  naturalism ;  and  I  suppose 
that  I  have  been  requested  to  contribute  a  Foreword  to  this  translation 
because  I  too  believe  that  all  attempts  at  scientific  interpretation  which  are 
other  than  naturalistic  are  worthless. 

Let  me  start  (Professor  Bianchi's  opening  chapter  justifies  such  a  de- 
parture) from  a  comprehensive  world-scheme  here  briefly  outlined  as  a  basal 
hypothesis  within  the  framework  of  which  (as  I  think)  any  naturalistic  inter- 
pretation should  find  a  place.  At  a  very  early  stage  of  evolution  there  were 
physical  events  only.  Protons  and  electrons  existed  in  such  whirls  of 
changing  relatedness  as  to  constitute  atoms.  Higher  kinds  of  relatedness 
than  those  we  name  physical  were  not  yet  in  being.  At  a  later  stage  the 
atoms  were  grouped  into  molecules  of  increasing  complexity  under  the  new 
kind  of  relations  we  call  chemical.  With  the  advent  of  lowly  organisms  a 
higher  kind  of  relatedness  (purely  natural),  which  we  call  vital,  comes  into 
the  picture.  At  a  yet  later  stage,  when  a  critical  point  in  the  development 
of  the  nervous  system  is  reached,  quite  new  kinds  of  relation,  which  we 
commonly  speak  of  as  conscious,  supervene.  Not  less  natural  than  their 
predecessors,  they  permit  of  profiting  by  previous  experience.  For  the 
present  we  need  carry  the  outline  sketch  no  further. 

What  are  the  salient  features  in  such  a  scheme  ?  They  are  (1)  that  new 
kinds  of  natural  relation  among  pre- existent  things,  or  groups  of  events, 
appear  at  succeeding  stages  or  levels  in  the  course  of  evolution  ;  (2)  that  their 
successive  appearance  is  to  be  accepted  "  with  natural  piety,"  as  Professor 
Alexander  puts  it ;  (3)  that  it  is  part  of  the  business  of  science  to  ascertain  the 
environing  conditions  which  contributed  to  their  appearance ;  but  (4)  that 
it  is  no  part  of  the  business  of  science  to  dally  with  such  explanations  as 
metaphysical  philosophers  may,  from  time  to  time,  suggest  in  terms  of  some 
supra-natural  agency  through  the  operation  of  which,  it  is  said,  they  so 
appear.  Such  explanations  may  well  be  true ;  but  they  have  no  place  in 
natural  science. 

The  position  may  perhaps  be  rendered  clearer  by  distinguishing  two 
kinds  of  implication  under  which  the  phenomena  may  be  interpreted.  In 
any  given  natural  system  what  takes  place  at  any  given  level  involves  con- 
current changes  at  lower  levels.  In  their  absence  it  does  not  occur.  Thus, 
conscious  profiting  by  experience  involves  physiological  changes  in  the  brain  ; 
these  again  involve  (within  the  system  of  the  organism)  less  specialised  vital 
11 


12  FOREWORD 

changes ;  and  these,  in  turn,  physico-chemical  events.  One  cannot  invest 
this  order  of  involution.  But  when,  in  the  course  of  world- progress,  a  new 
kind  of  relatedness  supervenes  at  any  given  level,  the  way  in  which  concurrent 
events  on  the  level  below  it  run  their  course  (what  Maxwell,  as  a  boy,  called 
their  "  particular  go  ")  depends  on  this  new  kind  of  relatedness.  Thus  all 
vital  changes  in  the  organism  "  involve  "  physico-chemical  events  and  trans- 
formations of  energy ;  but  the  particular  way  in  which  these  events  and 
these  transformations  occur  "  depends  on  "  the  presence  of  vital  relations. 
No  vitality  without  changes  of  energy  (involution)  ;  no  such  changes  of  energy 
without  vitality  (dependence).  In  concrete  fact  both  kinds  of  implication 
reciprocally  obtain  ;  but,  even  if  they  be  inseparable,  it  conduces  to  clearness 
of  thought  to  distinguish  them.  Progressive  development  of  novelty  is  the 
keynote  of  evolutionary  progress.  New  orders  or  kinds  of  relation  success- 
ively emerge  at  ascending  levels  (chemical,  vital,  mental)  ;  but  on  their 
emergence  much  novelty  in  the  course  of  events  at  lower  levels  thereafter 
depends. 

Now  apply  this  to  the  naturalistic  thesis  which  Professor  Bianchi  con- 
sistently advocates.  There  is  an  order  of  relatedness  which  we  call  mental. 
But  its  very  existence  involves  physiological  changes — or  (more  specifically) 
the  establishment  of  sets  of  permeable  neurone-routes — in  the  central  nervous 
system.  Let  us  so  far  follow  Semon  as  to  give  the  name  "  engram  to  a 
permeable  system  of  neurone-routes.  Then  the  naturalistic  thesis  may  be 
summarised  thus  :  Every  psychological  complex  involves  a  neural  engram. 
This,  of  course,  does  not  mean  that  a  complex  is  an  engram.  One  might  just 
as  well  say  that  a  tune  that  I  hear  is  a  gramophone  record.  None  the  less 
that  tune  which  I  so  hear  (with  some  paucity  of  higher  overtones)  involves 
such  a  record,  and  can  have  no  being  without  it.  But  the  making  of  the 
record  depends  on  reflective  thought.  So,  too,  the  establishment  of  an 
engram  may  depend — that  of  some  engrams  does  depend — on  acquired 
permeability  of  neurone-routes — permeability  which  would  not  come  into 
being  in  the  absence  of  mental  relations.  So  runs  the  naturalistic 
hypothesis. 

If,  then,  we  may  say  that,  for  evolutionary  naturalism,  every  psychological 
complex  involves  a  neural  engram,  inherited  or  acquired — or  (if  it  be 
preferred)  that  all  mental  events  involve  physiological  correlates — can  we 
follow  up  the  scheme  of  implication  (involution  and  dependence)  somewhat 
further  ? 

Professior  Bianchi  deals  in  careful  detail  with  two  cortical  levels  :  (a)  the 
frontal,  and  (6)  that  which  we  may  call  the  post-frontal,  including  the  tem- 
poral, parietal,  and  occipital  centres.  Development  of  the  frontal  region 
marks  a  relatively  late  stage  of  evolutionary  progress  (e.g.  in  mammals),  and 
this  development,  in  proportion  to  that  of  the  post-frontal  regions,  is  far  more 
extensive  in  man  than  in  the  monkey,  and  a  good  deal  more  extensive  in  the 
monkey  than  in  the  dog.  In  the  intact  animal  functional  action  in  the 
frontal  region  always  involves  that  of  the  post-frontal  and  perhaps  other  sub- 
ordinate centres ;  and  the  way  in  which  these  centres  then  play  their  part 


FOREWORD  13 

depends,  in  some  measure,  on  the  mental  complex  correlated  with  frontal 
engrams.  Now  the  manner  in  which  an  organism  behaves  is  held  to  afford 
(1)  from  the  physiological  point  of  view  an  index  of  engrammic  permeability 
of  neurone-routes,  and  (2)  from  the  psychological  point  of  view  a  basis  of 
inference  to  the  mental  complex  which  is  correlated  with  neuro- physiological 
process,  frontal  or  other. 

What,  then,  does  Professor  Bianchi  feel  justified  in  inferring  from  the 
behaviour  of  monkeys  from  whose  brains  the  frontal  cortex  has  been  ablated  ? 
That  they  are  reduced  to  the  level  of  unconscious  automata — at  any  rate  in 
one  sense  of  the  word  "unconscious."  In  what  sense?  Professor  Bianchi 
in  his  concluding  chapter  discusses  the  concept  of  consciousness  ;  and  he 
favours  the  hypothesis  that  two  stages  may  be  distinguished,  a  lower 
and  a  higher.  The  reactions  which  we  can  observe  in  animals  "  warrant 
us,"  he  says,  "  in  speaking  of  the  dawn  of  a  higher  consciousness  ;  and,  if  we 
trace  the  various  stages  in  the  evolution  of  the  brain,  we  find  that  they  first 
show  themselves  coincidently  with  the  first  appearance  of  the  frontal  lobes." 
If  this  be  so,  we  may  say  that  consciousness  of  the  higher  order — i.e.  that 
kind  of  consciousness  which  we  human  folk  enjoy — involves  the  integrity  of 
the  frontal  lobes.  Hence  one  seems  justified  in  speaking  of  the  mutilated 
monkey  as  in  this  sense  an  unconscious  automaton.  And  one  may  hope,  on 
humanitarian  grounds,  that  this  is  so  ;  for,  if  it  be  so,  then  with  the  destruc- 
tion of  the  frontal  cortex,  consciousness,  as  the  analogue  of  what  we  commonly 
mean  by  the  word,  ceases,  though  the  behaviour  of  an  automaton  is  still  open 
to  observation. 

The  question  then  arises  :  What  characterises  the  lower  stage  of  conscious- 
ness— that,  let  us  say,  which  is  correlated  with  post-frontal  function  ?  The 
answer  must  be  inferential  and  in  large  measure  conjectural.  It  may  be 
epiphenomenal  in  the  behaviourist  sense.  In  other  words  it  may  be  the  otiose 
accompaniment  in  sentience  of  post-frontal  process.  If  so,  no  part  of  the 
observed  behaviour  of  the  mutilated  monkey  depends  on  its  presence ;  for 
sentience  is  then,  in  Huxley's  metaphor,  merely  the  steam- whistle  of  the  post- 
frontal  engine,  exercising  no  influence  on  its  mode  of  running.  That,  how- 
ever, is  clearly  not  Professor  Bianchi' s  view.  The  mutilated  monkey,  as  he 
infers,  retains  much  capacity  for  the  simpler  forms  of  perception.  Further- 
more, it  is  in  the  post-frontal  centres  that  "  images  "  are  in  some  sense 
retained.  A  difficult  matter  is  here  opened  up.  Any  such  expression  as  the 
retention,  storage,  or  preservation  of  images  is  highly  elliptical.  It  should, 
in  my  opinion,  be  avoided.  It  involves  the  introduction  of  a  psychological 
term  into  the  physiological  universe  of  discourse.  What  I  suppose  to  be 
retained,  physiologically,  is  not  an  image  but  a  set  of  permeable  neurone- 
routes  radiating  forth  from  any  given  sensory  centre.  It  is,  however,  no  part 
of  my  purpose  to  enter  into  a  question  which  admits  of  different  answers 
(apart  from  the  connotation  of  the  words  we  use)  in  accordance  with 
divergent  interpretations  of  the  observed  facts. 

In  accordance  with  the  scheme  I  have  outlined  as  a  basis  for  reference, 
we  may  regard  frontal  structure  and  function  as  affording  evidence  of 


14  FOREWORD 

a  higher  level  or  stage  of  physiological  evolution  than  does  post-frontal 
structure  and  function.  A  superior  order  of  consciousness  is  correlated 
with  the  former;  an  inferior  order  is  correlated  with  the  latter.  Now 
all  the  evidence  goes  to  show  that  language  depends  on  the  higher  mental 
processes  correlated  with  the  functional  activity  of  the  frontal  lobes. 
But  all  the  evidence  goes  also  to  show  that  speech-centres  are  localised  in 
certain  parts  of  the  post-frontal  regions.  Is  it  a  valid  criticism  to  urge  that  the 
evidence  is  therefore  contradictory  ?  Surely  not.  There  is  nothing  contra- 
dictory in  saying  (1)  that  speech  depends  on  higher  mental  process,  and 
(2)  that  language  involves  the  appropriate  functioning  of  post-frontal  centres. 
Nay,  rather  it  is  in  strict  accord  with  the  general  principles,  that  (1)  what 
takes  place  at  a  higher  level,  in  which  new  relations  obtain,  involves 
lower-level  events ;  and  that  (2)  the  particular  way  in  which  these  events 
run  their  course  depends  on  the  new  relations  which  obtain  at  the  higher 
level. 

If  Professor  Bianchi  is  right  in  correlating  the  higher  mental  processes 
which  may  be  inferred  from  the  behaviour  of  mammals  with  the  functional 
activity  of  the  frontal  lobes,  then,  since  this  part  of  the  brain  is  so  highly 
developed  in  man,  it  falls  well  within  his  province  fully  to  discuss  the  part 
which  intellect,  sentiment,  and  human  sociality  have  played  in  the  advance 
of  civilisation.  In  any  case  his  treatment  of  these  matters  will  awaken  wide 
interest,  and  will  stimulate  further  inquiry.  The  position  is,  however,  some- 
what peculiar.  There  are,  broadly  speaking,  three  sets  of  people.  There  are 
the  supra-naturalists  (if  I  may  so  call  them),  who  assert  that  Mind,  in  its 
proper  and  disparate  order  of  being,  with  its  prerogative  of  "  pure  memory," 
does  not  "  involve  "  any  brain-changes,  frontal  or  other,  save  in  so  far  as  it 
acts  on,  or  into,  or  through,  the  organism  it  has  created  for  its  use  and  has  to 
some  extent  automatised.  On  the  other  hand  there  are  the  behaviourists 
(pur  sang)  who  say  that  conscious  relations  count  for  nothing  in  the  course 
of  events.  At  most  they  are  luxurious  adjuncts  devoid  of  business  capacity. 
Behaviour  gets  along  quite  comfortably,  they  say,  without  any  supposed 
dependence  on  the  kind  of  mental  relations  which  introspective  psychologists 
have  invented.  To  neither  of  these  sets  of  people  does  Professor  Bianchi 
belong.  As  man  of  science  he  rejects  supra-natural  influx  ;  but  he  accepts 
mental  relations  as  counting  for  all  they  are  worth  in  the  progress  of  man. 
He,  with  his  associates  (and  most  evolutionists  are  here  his  associates),  says 
that  mental  development  always  involves  development  of  the  brain.  He  has 
now  adduced  cogent  evidence  in  support  of  the  further  contention  that  higher 
mental  development  is  correlated  with  the  activity  of  the  frontal  brain.  It 
follows  that  the  mental  processes  of  which  civilisation  is  the  expression  have 
physiological  correlates  in  the  frontal  lobes.  But  when  we  turn  to  the  fuller 
discussion  of  these  mental  processes,  we  find  that  the  activity  of  the  frontal 
lobes  is  rather  tacitly  taken  for  granted  than  called  on  as  an  aid  to  the  inter- 
pretation of  human  thought.  Not  much,  as  yet,  has  the  neuro-physiology  of 
the  frontal  lobes  been  able  to  contribute  to  the  elucidation  of  the  psycho- 
logical matters  on  which  Professor  Bianchi  so  ably  discourses.  That  the 


FOREWORD  15 

frontal  region  is  in  functional  activity  during  all  mental  process  is  no  doubt 
taken  for  granted  ;  but  just  how  it  so  functions  in  detail  remains  in  large 
measure  an  unsolved  problem.  It  is,  however,  those  who  work  on  the  careful 
lines  that  Professor  Bianchi  indicates  in  this  work  who  are  most  likely  to 
contribute  to  its  solution.  And  no  one  who  approaches  in  a  scientific 
spirit  the  problems  which  Professor  Bianchi  discusses,  can  fail  to 
appreciate  the  value  of  the  light  that  he  has  thrown  on  the  Mechanism 
of  the  Brain. 


TABLE   OF   CONTENTS 

CHAPTER  I 

PAGE 

EVOLUTION     OF     THE     NERVOUS     SYSTEM     AND     THE     CEREBRAL 

LOCALISATIONS         ......         1 

Mind  and  brain — The  brain  a  transformer  of  the  cosmic  energies 
— The  applicability  of  physical  theories  to  mind — The  reduction  of 
the  phenomena  of  life  and  the  energies  whence  they  are  derived  to 
universal  laws — Process  of  composition  and  decomposition  of  the 
images  and  thoughts — Chemical,  physical,  and  mechanical  nature  of 
the  reactions  of  the  lower  animals — Tropisms,  differential  sensibility 
and  associative  memory — The  mechanism  of  the  reactions  increases  in 
complexity  with  the  development  of  the  nervous  system  and  of  the 
brain  in  particular — The  origin  of  the  higher  mental  processes  to  be 
sought  for  in  the  natural  history  of  life  and  in  the  evolutionary  phases 
of  the  nervous  system — The  optic  lobes  and  optic  thalamus — The 
thalamus  prepares  the  sensory  waves  destined  for  the  further  elabora- 
tion of  the  cerebral  mantle — The  functional  products  of  pre-existing 
nervous  organs  are  indispensable  for  the  elaboration  of  the  more 
complex  products  of  the  organs  of  more  recent  development — Func- 
tional differentiation  of  the  cerebral  mantle  and  cerebral  localisations 
— Modern  conception  of  the  doctrine  of  the  localisations — The 
sensory  areas — Are  there  cortical  organs  which  subserve  the  function 
of  the  higher  mental  processes  ? — The  associative  zones  of  Flechsig — 
Criticism  of  the  doctrine  of  Flechsig — The  function  of  that  part  of  the 
posterior  associative  zone  of  Flechsig  known  as  the  inferior  parietal 
lobule — What  we  learn  from  clinical  syndromes  depending  upon 
lesions  of  the  left  inferior  parietal  lobule — Clinical  cases — The  function 
of  the  temporal  lobe  (anterior  part  of  the  posterior  associative  zone 
of  Flechsig) — Clinical  and  anatomico-pathological  observations — The 
cortical  motor  area  and  the  intermediate  or  evolutionary  motor  area 


CHAPTER  II 

HISTORY   AND    EVOLUTION    OF    THE    DOCTRINE    CONCERNING    THE 

FUNCTIONS  OF  THE  FRONTAL  LOBES  .  .  .67 

Hypotheses  bearing  upon  the  function  of  the  extensive  cortical  field 
situated  in  front  of  the  motor  zone — Gall  and  Spurzhein,  Fleurens, 
Gratiolet,  Hitzig,  Ferrier,  Bianchi,  Munk,  Goltz,  Moolman,  Loeb, 
Luciani,  Wundt,  Meynert,  Sciamanna,  Libertini,  Fano,  Polimanti, 
»  Shepherd,  Roncoroni,  Lugaro,  Monakow,  Rossolino,  Bechterew 

17 


PAG 


18  TABLE  OF  CONTENTS 

CHAPTER  III 

EVOLUTION,  MORPHOLOGY,  AND  STRUCTURE  OF  THE  FRONTAL  LOBE   94 

The  law  of  development  of  the  cerebrum  and  especially  of  the  cortex 
is  confirmed  by  the  evolutionary  story  of  the  frontal  lobe — Brains  of 
fishes,  amphibians,  and  reptiles — Volumetric  relations  between  the 
optic  lobes  and  the  fore-brain — Brains  of  rabbit,  dolphin,  and  dog — 
Only  in  the  higher  mammals  do  we  begin  to  find  an  appreciable 
frontal  lobe — Frontal  lobes  of  the  dog,  horse,  and  ruminants — The 
author's  investigations  of  the  brain  of  the  sheep — Frontal  lobe  of 
the  macaque,  cebus,  and  the  orang-utang — Proportion  of  the  cortical 
surface,  total  volume  of  cortex,  and  richness  in  cells  in  the  middle- 
grade  monkey,  the  orang-utang,  and  man— The  frontal  lobe  of  man — 
The  inexcitable  precentral  area — The  intermediate  precentral  area — 
The  frontal  area  of  the  frontal  lobe— The  pre-frontal  area,  properly 
so  called — The  morphology  of  the  human  frontal  lobes — The  cyto- 
tecture  of  the  frontal  lobe — Indications  of  evolution  of  the  frontal 
lobe  in  man  —  Functional  differences  between  the  right  and  left 
frontal  lobes 


CHAPTER  IV 

METHODS  OF  INQUIRY  .  .  .  .  .  .121 

The  difficulties  of  investigation  justify  criticism — Critical  observa- 
tions of  Schafer  and  Monakow — Shepherd's  investigations  carried  out 
out  on  the  lines  laid  down  by  Schafer — Functional  compensation  and 
degenerations  consecutive  to  experimental  mutilations  are  sources 
of  errors — Objections  raised  against  the  use  of  mammals  in  investiga- 
tions bearing  upon  the  functions  of  the  frontal  lobes — Experiments 
reported  in  this  work  furnish  sufficient  confirmatory  data  of  the 
capacity  for  precise  perceptions,  judgments,  comparisons,  memory 
and  new  adaptations  in  the  cebus — The  intensity  of  the  current 
employed  to  excite  the  cortex  may  be  the  cause  of  error — Errors 
may  arise  from  the  fact  that  limited  extirpations  of  one  frontal  lobe 
do  not  produce  noteworthy  disturbances  —  Relation  between  the 
extent  and  the  effects  of  mutilation 


CHAPTER  V 

^/ CLINICAL  AND  EXPERIMENTAL  HISTORIES    OF    DOGS,   FOXES  AND 

MONKEYS,  INCLUDING  CONTROLS     ....     137 

1,  2,  3,  control  experiments — 4,  5,  removal  of  the  frontal  lobes  of 
the  dog  and  the  fox — 6,  7,  8,  9,  10,  11,  12,  13,  experiments  on  monkeys 
— Summary  of  the  experiments — Modifications  of  the  perceptive, 
attentive,  and  associative  capacities,  of  the  sentiments  and  of  the 
conduct  in  monkeys  as  the  result  of  the  mutilations 


TABLE  OF  CONTENTS  19 

CHAPTER  VI  PAGE 

THE  EXCITABLE  CORTICAL  AREA  OF  THE  FRONTAL  LOBE   AND  ITS 

SIGNIFICANCE  .  .  .  .  .  .          .187 

Literature  of  experiments  showing  the  existence  of  small  motor 
fields  in  the  frontal  lobe  for  movements  of  the  eyes,  pupils,  and  ears — 
Disposition  and  topography  of  these  areas — The  author's  experiments 
—Difficulty  in  interpretation — Are  there  special  fields  for  the  motor 
concomitants  of  the  higher  mental  processes  ? — Experiments  on  the  t^^~ 
human  subject  lend  probability  to  such  a  hypothesis — Visual  dis- 
turbances in  dogs  and  monkeys  that  have  suffered  mutilation  of  the 
frontal  lobes — Tentative  interpretations  of  the  phenomenon — Is  it 
a  question  of  diaschisis  (disturbance  at  a  distance)  ? — Monkeys 
mutilated  in  both  frontal  lobes  lose  the  alert  and  mobile  glance  char- 
acteristic of  these  animals  and  assume  an  appearance  that  reminds 
us  of  human  dements 

CHAPTER  VII 

ASSOCIATIVE  PATHS  BETWEEN  THE  FRONTAL  LOBE  AND  THE  SENSORY 

AREA  OF  THE  CORTEX          .  .  .  .  .198 

Superior  or  arcuate  longitudinal  bundle,  the  occipi  to -frontal  bundle, 
the  cingulum,  their  origin,  course,  and  termination — Does  the  internal 
capsule  receive  projection  fibres  from  the  frontal  lobe  ? — Does  there 
exist  a  fronto-pontine  bundle  and  a  fronto-ponto-cerebellar  bundle  ? — 
Relation  of  the  frontal  lobe  with  the  caudate  nucleus,  the  putamen, 
and  the  claustrum — The  results  of  the  author's  investigations  confirm 
the  existence,  in  monkeys,  of  bundles  establishing  reciprocal  relations 
between  the  frontal  lobes  and  the  rest  of  the  cerebral  mantle 

CHAPTER  VIII 
INTELLIGENCE  AND  LANGUAGE  .  ....     209 

Intelligence  should  be  examined  by  the  naturalist  exclusively  from 
the  biological  point  of  view — A  more  realistic  conception  of  life,  in- 
telligence, and  morality  is  to  be  derived  from  the  examination  of  facts 
than  can  be  obtained  from  ideative  abstractions,  however  brilliant — 
Intelligence  is  not  exempt  from  the  general  laws  that  apply  to  cosmic 
energy,  including  the  laws  of  quantity — Intelligence  with  its  power  of 
penetration  into  the  cosmic  and  social  environment  displays  a  bio- 
phylactic  function — The  whole  mental  edifice  rests  upon  the  mechan- 
ism of  the  associations — Consciousness  and  the  unconscious — Language 
—The  law  of  evolution  is  the  supreme  law  of  thought  and  speech — 
Origin  and  evolution  of  language — Physiological  fusion  of  the  con- 
crete images  of  things  with  those  of  the  words  which  symbolise  them — 
Anatomical  substratum  of  both  of  these — Abstract  conceptions  and 
language — Intrinsic  constituent  elements  of  speech  and  their  anatomi- 
cal basis — The  evolution  of  the  cortical  fields  of  language — Increasing 
complexity  of  the  intellectual  and  linguistic  mechanism  with  the 
advance  of  knowledge — Part  played  by  the  frontal  lobes  in  the  con- 
struction and  expression  of  thought  and  in  human  conduct — Parallel- 
ism between  human  imbeciles  and  animals  mutilated  in  the  frontal 
lobes — Logic — The  evolution  of  logic  coincides  with  the  evolution  of 


20  TABLE  OF  CONTENTS 

CHAPTEK  VIII — continued 

PA(4E 

the  brain  and  of  language — Logic  and  the  norms  of  exact  knowledge 
— Defects  of  logic  due  to  evolutionary  defects  or  to  morbid  processes 
in  the  brain — Logic  as  a  biophylactic  function,  a  thesis  confirmed  by 
cerebral  pathology 

APPENDIX.     LOGIC         .......     252 

CHAPTER  IX 

EMOTIONS  AND  SENTIMENTS  .  .  .  .  .  .260 

General  conception  of  emotions — Physical  agents  and  their  influence 
— The  kinsesthetic  sense — All  the  organic  functions  are  represented 
in  the  cerebral  cortex — Experimental  proofs — The  fundamental 
emotions — The  higher  or  intermediate  emotions — The  anatomical 
field  of  the  organic  phenomena  accompanying  the  fundamental 
emotions  is  situated  posteriorly  to  the  frontal  lobe— Psychosomatic 
characters  of  pleasure  and  of  pain — The  James-Lange  doctrine — 
Its  vulnerable  side — Sentiments  represent  a  higher  evolutionary 
grade  of  the  fundamental  and  intermediate  emotions — Desire — The 
sentiments  and  not  the  emotions  disappear  after  mutilation  of 
the  frontal  lobes — Sociality — Its  evolution — Imbeciles  are  asocial 
— Is  sociality  an  instinct  ? — Elements  which  contribute  to  the 
more  rapid  development  of  sociality  amongst  civilised  peoples — 
Human  solidarity — The  sentiment  of  sociality  makes  its  appear- 
ance coincidentally  with  the  development  of  the  frontal  lobes  in 
mammals — It  disappears  after  frontal  mutilations,  although  the 
primary  and  intermediate  emotions  remain,  sometimes  exalted 

APPENDIX.     THE  SOCIAL  SENTIMENT  ....     286 

CHAPTER  X 

CONSCIOUSNESS  .  .  .  .  .  .  .  •  302 

Modern  conception  of  consciousness — Its  limits  with  regard  to  un- 
conscious thought — Its  evolution —  Constituent  elements — Its  orienta- 
tion in  time  and  space — The  two  hypotheses  regarding  the  extent 
to  be  assigned  to  the  conception  consciousness — The  utilisation  of 
experience  which  contributes  to  the  evolution  of  consciousness 
coincides  with  increase  of  the  nervous  mass — The  sum  of  the  mnemonic 
traces  and  the  conflict  occurring  in  the  case  of  actual  perceptions  or 
representations  with  their  impulses  appear  to  be  characteristic 
features  of  an  enlightened  or  higher  consciousness — Insufficiency 
of  the  hind  brain  in  relation  to  the  development  and  manifestation  of 
the  higher  consciousness — This  coincides  with  development  of  the 
frontal  lobes — The  study  of  retarded  or  arrested  evolution  of  the 
human  brain  allows  us  to  retrace  the  story  of  the  evolution  of  con- 
sciousness— The  movement  of  ideas  and  of  emotions  in  consciousness 
—The  uncoi  scious  and  the  subconscious — Inhibitory  power,  higher 
consciousness,  and  the  frontal  lobes — The  physical  law  of  inhibition 
— Conduct,  the  resultant  of  impulsions  and  inhibitions — Anatomical 
psychology  of  conduct — Applications  of  Anatomical  Psychology  to 
pedagogy 


THE 

MECHANISM   OF  THE  BRAIN 


CHAPTER  I 

Evolution  of  the  Nervous  System  and  the  Cerebral 

Localisations 

PSYCHIC  facts  compel  us  to  presume  the  existence  of  organs  of  a  particular 
structure  whence  emanate  energies  which  we  conclude  to  be  intrinsic  in 
their  substance,  and  laws  regulating  these  energies.  The  brain  is  the  ..great_ 
factory  of  thought.  To  it  are  directed  all  the  forces  of  nature,  forces 
whicjL  for  thousands  of  years,  have  been  expending  themselves  upon  it  and 
impressing  on  it  a  slow  and  continuous  motion  of  evolution. 

The  brain  in  turn  transforms  these  cosmic  forces  into  another  form  of 
energy  which  possesses  analogous  properties,  which,  indeed,  summarises, 
accumulates,  integrates  and  utilises  them  all  in  the  process  of  thought  and 
for  the  purposes  of  life. 

The  great  problem  that  confronts  us  is  to  determine  in  what  manner  and 
liv  what  mrans  the  transformation  of  these  energies  (external  stimuli)  takes 
place.  How  are  vibrations  of  ethereal  matter  transformed  into  psychic 
products,  or,  in  other  words,  what  is  the  process  of  mentalisation  or 
spiritualisation  of  matter  to  which  the  elementary  phenomena  of  mind  may 
be  reduced  ?  That  question,  however,  cannot  even  to-day  receive  a  plausible 
reply  unless  it  be  in  the  form  of  hypothesis,  or  even  of  pure  and  simple 
conjecture. 

The  marvellous  progress  attained  in  physical  science  provides  us  with 
data  that  are  full  of  value  and  hope  for  psychology.  The  doctrine  of  the 
electrons  has  thrown  a  flood  of  light  on  this  vexatious  and  tormenting 
problem,  and  as  a  result  it  would  seem  legitimate  to  inquire  whether  the 
nervous,  and  therefore  also  the  psychic  processes,  at  least  the  more  element- 
ary of  these,  are  not  to  be  regarded  as  the  product  of  transformation  of  a 
special  localised  condition  of  the  universal  ether  into  a  still  more  localised 
and  specialised  one  which  we  call  nerve-waves,  which,  in  turn,  are  resolved 
into  sensations  and  images  (percepts)  and  might  be  considered  the  equiva- 
lents of  atoms  of  matter  launched  from  afar.  Admittedly,  this  is  all  very 
hypothetical,  but  one  cannot  help  thinking  there  is  in  it  a  germ  of  truth. 

Many  physicists  after  Helmholtz    (amongst  the  Italians,   Rhigi l)   are 

1  Rhigi.     La  moderna  teoria  dei  fenomeni  fisici.     Bologna,  1904. 
A  1 

* 


2  TH1E:  M^CHAklSM'  OF  THE  BRAIN 


inclined  to  favour  the  view  that  electrons  —  "  those  atoms  of  negative  elec- 
tricity, provided  with  mass  of  an  electro  -magnetic  nature  and  varying  accord- 
ing to  velocity  "  (Cantoni)  —  do  not  become  fused  in  one  homogeneous  whole 
but  preserve  their  individuality.  If  this  were  the  case  it  would  be  reasonable 
to  suppose  that  the  groups  of  electrons  constituting  an  image  are  not  blended 
into  one  uniform  whole,  nor  the  innumerable  images  that  go  to  make  up 
the  mind  into  another  uniform  product,  but  preserve  their  individuality 
in  each  brain  and  correspond  in  different  brains  according  to  fixed  laws. 
This  much  is  certain  that,  casting  a  rapid  glance  over  the  development  of 
the  human  mind,  we  seem  to  behold  a  progressive  assimilation  of  nature  on 
the  part  of  the  psyche  and  a  progressive  penetration  of  the  collective 
intelligence  into  the  world  and  its  forces,  so  that  with  these  it  becomes 
integrated  and  rises  essentially  to  the  consciousness  of  the  universe. 

There  is  an  analogy  that  is  worthy  of  mention  in  this  connection.  If 
we  make  a  close  examination  of  evolved  mental  life  we  seem  to  behold  a 
continuous  motion  of  composition  and  decomposition,  of  integration  and 
disintegration  of  images  and  thoughts  (hence  of  states  of  consciousness), 
differing  in  no  way  from  what  happens  in  the  material  interchange  in  living 
organisms  and  in  brute  matter  —  the  continual  transformation  of  the 
component  elements  as  the  result  of  reciprocal  chemical  action. 

All  impressions,  indeed,  excite  a  process  of  composition  that  varies 
extremely  in  men  of  different  structure.  There  are  associative  fields  which 
behave  in  a  thousand  different  ways  in  different  individuals  under  the 
influence  of  identical  stimuli  and  undergo  many  variations  in  the  same 
individual.  The  sight  of  the  sea,  for  example,  awakens  in  the  poet  the 
melancholy  song  of  the  distant  navigator  who  has  bade  Adieu  to  his  loved 
ones.  In  the  merchant  it  arouses  a  series  of  notions  concerning  lines  of 
navigation,  merchandise,  exchange  values  and  economic  intuitions,  and 
aspirations  after  wealth.  The  sight  of  a  woman  —  i.e.  the  vibrations  which, 
proceeding  from  a  body  illuminated  in  space,  reach  the  retina  —  produces  in 
one  man  a  simple  image  which  remains  photographed  in  the  brain  more  or 
less  distinctly.  In  another  man  it  gives  rise  to  a  series  of  aesthetic  emotions 
which  arise  from  harmony  of  form,  along  with  a  tendency  to  draw  near. 
To  the  ordinary  man  it  is  the  infatuation  of  woman,|  to  the  poet  the  more 
felicitous  picture  of  a  night  of  love,]  which  the  whole  world  may  behold. 
Now,  when  we  bear  in  mind  the  fact  that  not  only  very  simple  mental  forma- 
tions, the  sole  acquisitions  of  men  of  inferior  calibre,  but  also  complex 
ones,  such  as  those  that  scintillate  from  superior  brains,  sometimes  of 
unexpected  importance  and  unforeseen  consequence,  are  prepared  in  obscure 
cerebral  workshops  from  elements  in  the  greatest  variety  and  diversity  of 
combinations,  elements  which  in  most  cases  are  pre-  existent  and  identical 
in  different  brains  and,  further,  that  the  material  furnished  by  the  whole 
cerebral  mantle,  or  a  great  part  of  it,  is  derived  from  a  process  of  decomposi- 
tion and  recomposition  (association),  the  ultimate  products  of  which  rise  to 
the  light  of  consciousness  and  of  the  universal  intellect,  it  seems  to  me  one 
might  suggest  a  tentative  interpretation  on  the  lines  of  that  already  employed 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  3 

by  physicists  in  the  case  of  the  theory  to  which  allusion  has  been  made — 
viz.  the  deformation  of,  and  the  elastic  vicissitudes  special  to,  ether,  or, 
again,  electric  dissociation  consisting  in  the  separation  of  negative  electrons 
from  neutral  atoms,  a  separation  which  affords  an  explanation  of  chemical 
mutations  in  bodies.  The  writer  is  not  sure  if  this  conception,  which  he  put 
before  a  gathering  of  scientists  in  Naples  in  1 909, 1  harmonises  with  the  idea 
of  Loeb,  who  would  adopt  the  term  associative  hysteresis  as  corresponding 
to  associative  memory,  by  analogy  with  the  posthumous  facts  denned  by 
physicists  as  hysteresis.  In  any  case  there  is  something  to  be  said  for  having 
taken  the  luminous  impressions  that  go  to  form  visual  images  as  an  example, 
because  Maxwell  already  had  regarded  luminous  waves  as  electro -magnetic 
waves,  a  doctrine  which  found  further  support  in  the  experiments  of 
Hertz,  Lorentz  and  Rhigi.  Then  again,  the  fact  that,  by  varying  the 
disposition  of  apparatus  designed  to  produce  electro-magnetic  waves  we 
can  reproduce  ordinary  luminous  waves,  allows  us  for  the  moment  to 
embrace  the  hypothesis  that  luminous  waves  are  transformed  as  soon  as 
they  reach  the  retina  into  the  equivalent  of  the  electro -magnetic  waves. 
These  we  may  regard  as  the  nervous  waves,  as  already  supposed  by 
Dubois-Reymond. 

To-day  more  than  ever  there  is  a  tendency  on  the  part  of  physicists  to 
bring  the  phenomena  of  nature  and  the  energies  whence  they  are  derived 
under  identical  laws  and  to  recognise  in  them  all  one  single  force.  We 
know,  in  fact,  that  the  particles  which,  with  their  rapid  motion,  constitute 
the  cathodic  rays  are  nothing  else  than  negative  electrons,  and  that  a  body 
exposed  to  the  action  of  the  ultra-violet  rays  emits  electrons.  It  is  known 
also  that  there  is  probably  a  correspondence  between  the  chemical  valences 
and  the  function  of  certain  electrons  contained  in  the  atom — those  less  tied 
to  the  positive  nucleus— and,  therefore,  that  electrons  are  the  intermediaries 
between  matter  and  the  cosmic  ether  (Cantoni) .  If  it  be  true  that  the 
Rontgen_rays  are  only  manifestations  of  ethereal  waves  generated  by  abrupt 
variations  in  velocity  of  the  electrons  (which  seems  to  be  the  conclusion  to  be 
drawn  from  a  series  of  investigations  that  have  given  marvellous  results) 
we  might  conclude  with  modern  physicists,  as  did  Matteucci  a  good  few  years 
ago,  that  there  is  but  one  only  force  which  assumes  different  appearances  and 
behaves  differently  according  to  the  special  circumstances  of  the  means  by 
which  and  of  the  bodies  whence  it  is  displayed. 

The  researches  of  Loeb  2  are  of  great  value  in  this  connection.  The 
phenomena  of  tropism  so  diligently  investigated  by  this  physiologist,  who  is 
inclined  to  connect  them  with  the  colloidal  substances,  regarded  by  some 
as  the  engine  of  the  vital  phenomena,  throw  a  new  light  on  the  genesis  and  '. 
essence  of  psychic  phenomena.  No  doubt  the  continual  motion  of  ideas 
in  the  brain  corresponds  to  the  constant  transformation  of  matter,  to  the 
perennial  motion  of  the  energies  which  bodies  emit  and  absorb  at  all 

1  Bianchi.      "  La   meccanica   del   cervello    e    la   doppia    coscienza."      Atti   del 
Congresso  delle  scienze.     1910. 

2  Loeb.     Comparative  Physiology  of  the  Brain  and  Comparative  Psychology. 


4  THE  MECHANISM  OF  THE  BKAIN 

temperatures,  and  to  the  continuous  metabolism  of  things  in  general,  such 
as  the  motion  of  the  stars. 

Any  conception  can  be  divided  into  its  constituent  elements  by  a  process 
of  analysis,  just  as  a  chemist  does  with  any  organic  or  inorganic  substance 
when  he  reduces  it  to  its  elementary  components,  the  syntheses  of  which 
he  expresses  in  more  or  less  complex  formulse.  Even  what  appear  to  be  very 
simple  images  are  composed  of  several  elements  with  different  and  extensive 
anatomical  bases,  elements  to  which  we  can  apply  the  atomic  or  ionic  laws 
in  so  far  as  affinities  are  established  between  them,  so  that  in  all  men  the 
same  psychic  compounds  are  met  with  (perceptive  uniformity] ,  while  at  the 
same  time  an  infinity  of  other  components  are  combined  with  one  another 
in  an  incalculable  variety  of  ways,  giving  rise  to  products  which  differ  in 
different  individuals  either  in  some  slight  modality  or  in  actual  constitution. 
It  is  in  some  such  fashion  that  we  must  conceive  the  Law  of  Variation  which 
is  the  more  pronounced,  the  more  we  proceed  from  the  simple  to  the  complex, 
in  the  structure  of  the  mental  products. 

All  mental  components,  in  their  gradations  from  the  most  simple  to  the 
most  complex,  are  products  of  the  work  of  an  enormous  number  of  histo- 
logical  elements  distributed  throughout  the  human  brain,  elements  which 
apparently  have  gradually  become  specialised  for  particular  forms  of  work, 
capable  of  furnishing  specific  products  with  different  materials.  It  is  there- 
fore necessary  to  admit  the  existence  of  anatomical  relations  between  those 
morphological  groups  the  products  of  which  are  combined  together  so  as  to 
give  rise  to  mental  syntheses  which,  in  their  turn,  are  transmitted  into  the 
sphere  of  consciousness,  sometimes  to  be  launched  out  again  to  shed  light  on 
the  zenith  of  the  collective  and  universal  consciousness. 

The  number  of  these  paths  of  communication  between  one  cell  and 
another,  or  between  some  cell  groups  and  other  groups,  between  convolution 
and  convolution,  between  certain  cortical  areas  and  other  cortical  areas, 
near  or  remote,  defies  all  attempts  at  calculation.  If  we  could  estimate  the 
number  of  all  the  paths  that  have  been  constructed  between  different  com- 
munities, provinces  and  nations  ;  if  we  could  have  a  purview  of  all  the  net- 
work of  telegraphic  wires  extended  over  the  surface  of  the  world  or  traversing 
the  depths  of  the  ocean,  of  all  the  railway  lines,  and  ocean  paths  ploughed 
by  vessels  great  and  small,  of  the  entire  network  of  telephones  through  which 
circulate  infinite  thoughts  and  cares  which  arouse  and  agitate  an  incalculable 
number  of  interests,  which  in  synthesis  give  the  value  of  the  life  of  a  social 
group,  of  a  country,  of  entire  humanity,  we  should  yet  probably  fail  to  form 
the  faintest  idea  of  the  connections  which  morphology  and  histology  have 
shown  to  exist  between  the  cell-groups  of  the  cerebral  mantle  where  are 
formed  the  syntheses  that  give  the  measure  of  the  intellectual  value  of  each 
individual  and  which  serve  as  the  workshops  that  animate  the  collective 
life  in  the  different  and  varied  fields  of  human  activity. 

The  writer  feels  tempted  to  suggest  a  notable  analogy  between  the  world 
and  the  brain  in  this  regard,  without  compromising  himself  by  affirming 
whether  the  world  in  its  process  of  civilisation  is  modelled  on  the  evolution 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  5 

of  the  brain  or  whether  the  latter  becomes  evolved  along  with  the  physical 
and  social  world.     Further,  he  is  not  wholly  prepared  to  deny  the  hypothesis 
that  the  discharge  of  electrons  within  the  brain,  between  remote  or  neigh-/ 
bouring  groups  of  cells,  may  happen  independently  of  the  nervous  paths  of[ 
association. 


The  natural  history  of  the  evolution  of  the  nervous  system,  which  is  the 
latest  and  most  complex  form  of  organic  nature,  offers  confirmation  of  the 
law  long  recognised  by  chemists  in  dealing  with  the  affinities  of  brute  matter 
— viz.  that  bodies  found  to  be  of  a  very  complex  atomic  constitution 
lead  us  to  infer  the  existence  of  simpler  bodies  with  less  complex  atomical 
combinations  as  well  as  the  possibility  of  splitting  a  complicated  atomical 
formula  into  simpler  formulae.  This  law,  indisputable  in  chemistry,  is  strictly 
applicable  to  the  forms  of  life  and  to  the  apparatus  that  is  constantly  giving 
to  life  new  characteristics  and  varying  lines  of  action  as  well  as  ever -increasing 
energies.  This  apparatus  is  the  nervous  system. 

If  we  consider  the  nervous  system  from  the  point  of  view  of  its  chemical ,' 
constitution  or  of  its  structure  or  its  functions,  it  impresses  us  as  being  a  most 
complex  work  of  nature,  summing  up  all  the  cosmic  energies  in  one  vast 
combination  and  giving  a  new  expression  to  our  ideas  of  force. 

The  lowest  representatives  of  animal  life,  such  as  the  proto-amcebae, 
show  a  remarkable  homogeneity  of  their  protoplasm.  One  and  the  same 
substance  digests,  assimilates,  excretes,  breathes,  feels  and  moves. 

Differentiation  of  protoplasm  is  first  noticed  in  the  rhizopods  and  in- 
fusorians.  The  first  muscular  fibre  is  derived  from  epithelial  elements  by  a 
progressive  differentiation  giving  rise,  in  the  hydra,  to  the  so-called  neuro- 
muscular  cells  (Kleinenberg1).  These  cells  may  be  regarded  as  the  precursors 
or  germinative  elements  of  the  muscular  fibre  and  of  the  nerve-cells,  which 
we  find  quite  differentiated  from  one  another  in  the  higher  metazoans.  The 
common  origin  of  the  muscular  fibre  and  of  the  nerve-cell  is  not  admitted  by 
0.  &  K.  Hertwig,2  who  attribute  an  exclusively  muscular  significance  to  the 
so-called  neuro-muscular  cell,  otherwise  known  as  the  musculo-epithelial 
cell.  According  to  these  and  other  investigators,  the  nervous  substance 
develops  quite  independently  of  the  muscular  tissue.  The  two  authors 
above  mentioned  maintain  that  nervous  tissue  appears  with  certainty  in 
the  ccelenterates  and  is  composed  of  sensory  and  ganglionic  cells  (the  latter 
according  to  Havet  3  being  true  motor-cells).  The  musculo-epithelial,  the 
sensory  and  the  ganglionic  cells,  in  coelenterates,  are  derived  and  simultane- 
ously differentiated  from  the  epithelial  elements. 

1  Kleinenberg.        Eine      anatomisch-EntwicJclungsgeschichtliche        Untersuchung. 
Leipzig. 

2  0.    &   K.    Hertwig.      Das   Nervensystem  und  die  Sinnesorgane  der    Medusen. 
Leipzig. 

3  Havet.      "  Contribution  a  1'etude   du   systeme  nerveux  des    Actinies."      La 
Cellule,  t.  18. 


6  THE  MECHANISM  OF  THE  BEAIN 

Parker  1  has  demonstrated  the  presence  of  true  sphincters  in  sponges 
belonging  to  the  group  of  the  lower  metazoans  (Stylotella),  these  being 
formed  of  muscular  fibres  without  any  trace  of  nervous  elements.  This 
would  go  to  prove  that  these  muscular  fibres  contract  quite  independently 
of  the  intervention  of  any  nervous  elements  and  that  in  the  course  of  evolu- 
tion of  the  neuro- muscular  system,  the  muscular  fibre  appears  before  the 
nerve- cell.  If  we  trace  the  progressive  development  of  the  nervous  system 
up  to  that  of  man,  we  are  led  to  conclude  that  in  the  process  of  evolution, 
under  the  action  of  the  energies  of  nature,  the  nervous  tissue  becomes  in- 
creasingly developed  in  the  central  organ,  being  differentiated  in  accordance 
with  the  variations  assumed  by  the  forces  of  nature  and  that,  by  summaris- 
ing and  transforming  these  forces,  it  attains  the  dignity  of  an  organ  fitted 
for  the  spiritualisation  of  the  world. 

Between  the  earliest  appearance  of  nervous  substance  and  its  latest  grade 
of  development  there  is  only  a  morphological  and  numerical  progression  of 
nervous  elements  (even  though  it  be  not  constant)  and  a  proportionate  pro- 
gression of  the  reactive  capacity  of  the  living  being,  or,  in  other  words,  of 
corresponding  adaptations  to  the  environment. 

The  unfolding  of  the  nervous  system  follows  the  same  plan  as  the  evolu- 
tion of  life.  To  begin  with,  the  cells  which  receive  the  external  energies 
and  distribute  them  to  other  parts  of  the  small  organism  are  few  in  number. 
Later,  we  have  small  groups  of  cells,  almost  independent  one  from  the  other, 
more  or  less  regularly  distributed  amongst  equal  parts  of  the  larger  organism 
which  now  has  become  less  homogeneous,  as  in  the  medusae,  which  are 
provided  with  a  sensitive  ectoderm  innervated  by  a  specialised  nervous 
reticulum. 

The  nervous  system  undergoes  a  slow  but  progressive  evolution  from 
that  of  the  medusae  and  the  echinoderms  to  that  of  the  higher  insects,  the 
ants  and  the  bees,  in  which  we  find  a  noteworthy  feature  in  the  relative 
increase  of  the  nervous  mass,  with  greater  concentration  and  more  complete 
functional  differentiation  of  the  cellular  groups  (ganglia),  as  compared  with 
what  we  find  in  worms,  crustaceans,  arachnids  and  cephalopods. 

Parallel  with  the  development  of  the  nervous  tissue  we  have  that  of  the 
organs  of  the  body  and  in  particular  the  organs  of  the  senses.  The  visual 
organ,  e.g.,  makes  its  appearance  in  some  protozoans  (Pouchet,  Engelmann) 
with  the  so-called  ocular  spots,  composed  of  pigment  cells  which  have  the 
property  of  fixing  light. 

In  some  planarians  there  appears  a  group  of  nerve-cells  which  may  be 
regarded  as  a  rudimentary  brain,  and  at  the  same  time  we  have  the  very 
simplest  form  of  eye,  represented  by  cells  containing  granular  pigment  and, 
behind  these,  retinal  cells  from  which  an  optic  nerve  runs  to  the  rudimentary 
brain  just  mentioned.  In  the  higher  worms  the  anterior  cell-group  or 
ganglion  is  more  developed.  New  parts  have  been  added  to  the  eye  of  the 
lower  planarians  for  there  now  appears  a  refractive  medium  (nemertines  and 

1  Parker.  "  The  Reaction  of  Sponges,  with  a  Consideration  of  the  Nervous 
System."  Journal  of  Experimental  Zoology,  vol.  viii. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  7 

some  nematodes)  which  suggests  the  commencement  of  the  lens  ;  also  two 
anterior  nervous  ganglia  which  even  here  are  united  by  a  commissure. 

These  eyes,  still  of  a  simple  kind,  are  thus  in  relation  with  small  ganglionic 
groups  which,  after  successive  stages  of  development,  are  found  in  insects 
to  have  become  larger  and  more  complex  in  structure,  appearing  in  them 
as  peri-ossophageal  ganglia,  and  as  optic  lobes  in  fishes,  batrachians  and 
birds. 

We  know  well  what  stage  of  perfection  the  eye  reaches  in  the  vertebrates, 
especially  in  mammals,  and  the  degree  of  development  that  the  corresponding 
nervous  system  has  attained  with  the  superimposition  of  the  optic  thalamus 
and  the  cerebral  cortex,  and  we  know  that  the  numerous  eyes  of  some  insects 
do  not  permit  such  perfect  vision  as  that  possessed  by  the  higher  mammals. 
Sight  in  insects  is  of  a  very  low  order  and  probably  the  power  of  accommoda- 
tion (Lubbock)  and  of  distinguishing  the  contours  of  objects  (Forel)  is  absent. 
Wasmann  considers  that  ants  possess  visual  acuity  and  the  faculty  of  per- 
ceiving the  form  of  objects  but  this  is  not  very  likely.  The  perfection  of  the 
eye,  writes  G.  Bohn,1  has  permitted  the  formation  of  a  world  of  images  and 
with  this  there  has  occurred  a  true  psychic  revolution. 


* 
*  * 


Amongst  the  lower  living  orders,  reactions  assume  rather  a  chemical, 
physical  or  mechanical  character.  If  we  pass  an  electric  current  through 
water  in  which  some  ciliates  are  swimming  these  all  turn  their  heads  towards 
the  positive  pole.2  Again,  heat  accelerates  or  suspends  the  ciliary  move- 
ments according  to  its  degree.  A  capillary  tube  containing  certain  acids  or 
salts  induces  these  small  organisms  to  rotate  around  it  and  then  to  enter 
within  it  whilst  other  acids  or  other  salts  in  that  tube  will  make  them  migrate 
to  a  distance  from  it  (chemical  action).  These  small  organisms  can  be 
attracted  by  chemical  substances  that  may  yet  be  poisonous  in  nature,  and 
repelled  by  substances  that  are  actually  nutritive  (Pf effer  3) . 

Loeb  has  described  analogous  phenomena  in  starfishes  and  he  explains 
the  righting  movements  as  due  to  the  force  of  gravity  or  to  stereo typism. 
It  has  been  proven  that,  even  after  the  appearance  of  the  nervous  system, 
many  phenomena  regarded  as  of  psychic  nature  are  essentially  tropisms.4 

Anna  Drzewina  has  shown  that  if  a  crab  alters  its  direction  when  con- 
fronted by  a  rock  this  does  not  happen  as  the  result  of  reasoning  or  judgment 
followed  by  will,  as  Pieret  would  wish  us  to  believe  ;  it  is,  rather,  to  be 
regarded  as  a  mechanical  reaction,  for  the  simple  reason  that  this  animal 
behaves  in  identical  fashion  when  the  eyes  and  the  brain  (ganglia)  are 
removed. 

Many  manifestations  of  this  kind  are  due  to  chemical  or  physiogenetic 
variations  and  to  mechanical  or  kinetogenetic  variations,  and  accordingly 

1  Bohn.     La  naissance  de  V 'intelligence.     1909. 

2  Thornton.     Paper  read  to  British  Association.     1909. 

3  Pfeffer.      Untersuchungen  aus  dem  Botanischen  Instltut  zu  Tubingen.     Bd.  2. 

4  Max  Werworn.     Psychologische  Studien  der  Protisten. 


8  THE  MECHANISM  OF  THE  BEAIN 

many  observers  exclude  the  idea  of  any  truly  psychic  process.  To-day 
much  discussion  centres  around  the  question  as  to  where  psychism  really 
begins.  Many  support  the  doctrine  of  Lamarck,  who  would  attribute  psychic 
action  only  to  animals  possessing  a  well- differentiated  nervous  system. 
Others,  amongst  them  Bechterew,  even  go  so  far  as  to  admit  the  existence 
of  very  low  forms  of  psychism  in  orders  void  of  a  nervous  system. 
If  an  animal  with  a  differentiated  nervous  system — e.g.  an  ascidian — has  its 
nervous  ganglia  removed,  as  in  the  experiments  of  Loeb  and,  notwithstanding, 
continues  to  perform  movements  like  those  executed  under  normal  con- 
ditions, one  must  admit  that  even  in  those  creatures  the  so-called  phenomena 
of  psychism  are  but  the  results  of  reactions  of  the  living  matter  under  the 
direct  influence  of  the  forces  of  the  external  surroundings.  Bohn  l  introduces 
another  factor  between  tropism  and  psychism — viz.  differential  sensibility. 
Variability  of  reactions  is  a  condition  characteristic  of  psychism.  This  is 
distinguished  by  the  association  of  diverse  sensations  with  one  another 
and  of  present  with  past  sensations.  Bohn  insists  that  this  new  feature 
of  variability  of  reaction  is  founded  on  difference  in  sensibilities  (light, 
contact,  gravity,  chemical  action,  etc.),  and  in  degrees  of  intensity.  To 
this  is  to  be  added  another  factor  in  the  form  of  associative  memoty, 
mentioned  by  Loeb.2 

As  the  evolution  of  organisms  proceeds  apace,  more  especially  in  the 
matter  of  their  nervous  systems,  the  internal  variations  come  to  exercise  a 
strong  determinative  influence  over  the  reactions. 

The  reactions  of  tropisms  and  of  differential  sensibility  are  mechanical, 
physical  or  chemical  in  nature  ;  they  induce  internal  variations  and  are 
isolated  in  character.  With  the  intervention  of  association  of  sensations 
and  associative  memory  we  see  emerging  the  features  of  psychism.  Ants, 
e.g. ,  return  to  their  nests  as  a  result  of  visual,  tactile,  olfactory  and  mechanical 
stimuli,  the  associated  memory-residua  of  which  constitute  individual 
experiences  that  are  utilised  in  the  varying  circumstances  of  their  lives. 
We  can  also  conceive  a  new  factor  to  come  into  play  here,  inasmuch  as  the 
memory-traces  of  previous  sensations  may  represent  not  only  an  experience 
related  to  the  actual  sensation  but  a  latent  dynamism  and  a  tendency  toward 
determined  reactions. 

It  serves  no  good  purpose  to  discuss  the  particular  theories  of  this  or 
that  author  (Dantec,3  Radl 4  and  others)  concerning  this  question  of  mechani- 
cal, chemical  or  physical  action  ;  it  is  more  important  to  lay  stress  on  the 

notion  that  the  earliest  manifestations  of  psychic  life .in  other  words,  those 

reactions  that  present  the  features  of  volitional  or  reflex  attitudes — are  very 
probably  the  effect  of  chemical  or  physical  actions.  This  would  serve  to 
strengthen  the  hypothesis  that  with  the  appearance  of  the  nervous  system 
the  same  physical  and  chemical  forces  intrinsic  in  the  protoplasm  (biological 

1  Bohn.     LOG.  Git. 

2  Loeb.     LOG.  cit. 

3  Dantec.     Traite  de  Biologic.     1903. 

4  Radl.      Untersuchungen  ilber  dem  Phototropismus  des  Thiere.     1903. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  9 

equivalents)  become  gradually  transformed  into  nervous  equivalents  and 
with  progressive  development  of  the  nervous  system  into  psychic  equivalents. 

In  vertebrates,  concentration  of  the  small  nervous  masses  (ganglia) 
becomes  a  notable  feature.  The  two  chains  of  separate  ganglia  that  we  meet 
with  in  the  annelides  are  approximated  and  reincorporated  in  the  spinal 
medulla.  The  antennal,  optic,  supra-  and  sub-cesophageal  ganglia  become 
increasingly  larger  and  are  brought  into  more  intimate  associative  relations 
with  one  another,  whilst  to  these  there  becomes  added  another  nervous  mass 
— namely,  the  anterior  brain. 

The  cerebrum  of  vertebrates  in  its  earliest  manifestation  seems  to  be 
substituted  for  the  antennal  lobes  of  insects — which  in  them  are  quite  distinct 
tacto-olfactory  lobes — and  the  other  ganglia  above  mentioned,  and  it  presents 
a  new  formation,  the  anterior  brain,  the  cavity  of  which  communicates  with 
that  of  the  olfactory  lobe  in  the  case  of  fishes. 

The  first  representatives  of  the  latter  are  furnished  with  a  cerebral  cortex 
which  is  merely  a  thin  covering  consisting  of  epithelial  cells  (Edinger,1 
Jakob2). 

Throughout  the  different  classes  of  vertebrates  the  cortex  goes  on  develop- 
ing and  becoming  richer  in  nervous  elements  till  it  reaches  that  surprising- 
degree  of  development  which  we  find  in  the  higher  mammals,  where  it  is 
more  or  less  superimposed  on  the  representatives  of  the  old  ganglia  which 
were  the  only  nerve-centres  of  the  higher  invertebrates. 

The  development  and  differentiation  of  the  cells  of  the  cerebral  cortex 
proceed  almost  uniformly  from  fishes  to  the  higher  mammals,  reaching  the 
highest  grade  in  man,  whilst  at  the  same  time  the  cells  assume  much  closer 
relations  with  one  another  and  acquire  a  higher  functional  dignity. 

With  the  increase  of  the  nerve- elements  there  coincides  an  incessant 
assimilation  of  the  energies  of  nature,  which  we  commonly  speak  of  as  stimuli, 
these  giving  rise  to  that  functional  differentiation  whereby  the  number  of 
notions  and  adaptations  is  multiplied.  We  might  almost  say  that  nature 
becomes  revealed  to  itself  through  the  intermediary  of  the  nervous  system. 
A  wide  and  rigorous  application  of  the  experimental  method  enables  us  to 
detect  the  various  stages  of  development  of  the  nervous  system  and  of  the 
mind  throughout  the  animal  series  (phylogenesis)  as  well  as  in  the  individual 
(ontogenesis),  and  gives  good  general  grounds  for  stating  that  the  develop- 
ment of  mind  is  co-extensive  with  the  development  of  nervous  substance — 
i.e.  with  the  number  of  differentiated  elements — or,  in  other  words,  with  the 
successive  differentiation  of  notions  and  adequate  adaptations. 

Loeb's  statement  3  that  neither  the  weight  of  the  brain  nor  the  number 
of  nerve-cells  has  any  influence  on  the  degree  of  intelligence,  though  supported 
by  some  anthropological  researches  dealing  with  the  weight  of  the  human 
brain  in  civilised  and  non- civilised  races,  does  not  seem  sufficiently  well 

1  Edinger.      Vorlesungen  uber  den  Ban  der  Nervosen  Centralorgane,  etc.,  chap.  iii. 
1905. 

2  Jakob.      Vom  Thierhirn  zum  Menscherihirn.     1911. 

3  Loeb.     Loc.  cit. 


10  THE  MECHANISM  OF  THE  BRAIN 

founded  when  we  take  into  consideration  the  natural  history  and  comparative 
anatomy  of  the  brain. 

Growth  takes  place  in  greater  proportion  in  those  parts  of  the  brain  which 
are  last  to  appear — i.e.  in  the  hemispheres  or  rather  the  neopallium,  which 
by  degrees  assumes  an  enormous  size  in  comparison  with  the  mesencephalon 
and  the  posterior  brain. 

On  the  other  hand  the  number  of  nerve- elements  increases  progressively 
if  we  take  into  account  the  fact  that  not  only  is  the  grey  substance  of  the 
hemisphere  thicker  in  man  than  in  all  other  species,  but  it  is  also  incompar- 
ably more  extensive  owing  to  the  formation  of  convolutions  and  sulci  of 
considerable  depth,  whilst  at  the  same  time  it  is  much  richer  in  cells.1 


* 
*  * 


The  origin  of  the  highest  mental  processes  coexisting  with  that  modality 
of  mind  which  we  call  consciousness  is  not  to  be  sought  for  in  the  laborious 
and  exhaustive  effusions  of  metaphysicians  nor  amongst  postulates  founded 
|  on  the  analyses  of  logicians  nor  by  following  the  abstractions  derived  from 
introspection  but  rather  in  the  natural  history  of  life  and  in  the  phases  of 
evolution  of  the  nervous  system.  According  to  some  naturalists,  living 
things  are  so  many  chemical  machines.  If  this  be  so,  it  naturally  follows 
that  mental  activities  are  within  the  pale  of  that  vast  ocean  of  ether  in  which 
the  universe  swims,  and  are  subject  to  the  laws  that  regulate  the  energies 
which  penetrate  and  move  the  world.  In  a  later  chapter  this  matter  is  dis- 
cussed in  greater  detail.  Meanwhile  it  is  sufficient  to  state  that  the  majority 
of  physiologists  and  naturalists  are  agreed  that  manifestations  of  thought 
and  feeling  are  bound  up  with  the  dawning  of  life  and,  in  a  progressive 
manner,  with  reflexes  and  automatisms,  corresponding  with  the  development 
of  the  nervous  system. 

Intelligence  in  its  progressive  ascent,  manifesting  itself  as  a  vital  force, 
is  a  later  product  which  seems  to  be  almost  superimposed  upon  the  reflexes 
and  automatisms  just  as  these  succeed  and  are  intermingled  with  the 
phenomena  of  tropism.  Tropisms,  reflexes,  automatisms,  intelligent  re- 
actions, represent  phases  of  evolution  which  follow  one  upon  the  other 
without  interruption,  The  point  where  one  merges  into  the  other  cannot 
be  defined  because  there  is  no  distinct  or  essential  difference  in  their  nature. 
Although  automatisms  lose  their  conspicuous  identity  and  become  blended 
in  the  mechanism  of  intelligent  reactions,  yet,  if  looked  for,  they  can  still 
be  detected  in  the  complicate  structure  of  these  mental  products  which  are 
manifested  in  the  most  varied  reactions  of  living  beings,  in  their  physical 
and  ultimately  in  their  social  environment. 

The  first  cell-groupings  of  nervous  elements,  in  organisms  with  a  nervous 
system  now  differentiated  from  other  tissues,  may  be  regarded  as  organs  for 
the  transformation  of  the  forces  of  nature  into  nervous  waves  which  find 
resolution  in  reflexes  associated  with  phenomena  of  tropism,  and  next  in 

1  See  Chapter  III.  for  greater  detail. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  11 

automatisms  which  become  ever  more  complex  and  regulate  the  adaptations 
of  living  creatures  to  their  environment. 

With  the  further  development  of  additional  groups  of  cells  and  new 
paths  of  communication  between  them,  the  earliest  reflexes  become  com- 
plicated with  others  that  are  less  simple  in  character.  In  the  reactions 
of  creatures  with  a  more  evolved  nervous  system  new  nervous  organs 
come  into  play,  and  these,  in  turn,  acquire  new  and  more  complex 
co-ordination. 

In  the  lower  vertebrates — e.g.  in  Necturus  and  in  the  frog — the  mid-brain 
assumes  great  importance  as  a  centre  for  the  reception  and  elaboration  of 
acoustic,  visual  and  tactile  nerve- waves  and  the  corresponding  reflexes. 
The  optic  thalamus,  now  in  course  of  formation,  still  receives  a  few  optic 
fibres  directly  and  has  no  well-defined  function.  As,  however,  new  paths 
become  developed  and  new  cell-groups  come  into  existence  in  the  optic 
thalamus  of  the  more  evolved  species,  the  reflexes,  or,  rather,  the  reactions 
become  more  complicate  and  of  a  higher  order  than  the  reflexes  of  the  mid- 
brain.  The  feature  that  is  now  gradually  coming  into  evidence  is  the  wider 
extent  and  greater  variability  of  the  associations,  so  that  by  degrees  animal 
reactions  lose  their  former  characters  of  simplicity  and  relative  immuta- 
bility, and  this  is  especially  the  case  when  the  cerebral  cortex  makes  its 
appearance. 

The  optic  thalamus  is  an  organ  which  prepares  sensory  waves  for  further 
elaboration  in  the  sensory  cortex,  which  meanwhile  is  developing  and  becom- 
ing superimposed  on  the  optic  lobes  and  the  optic  thalami.  In  the  higher 
fishes  and  also  in  the  lower  batrachians  the  cerebral  mantle  is,  in  the  main, 
an  olfactory  formation.  Its  simplicity  is  a  very  characteristic  feature  in 
fish  and  the  lower  amphibians,  especially  when  we  compare  it  with  what  we 
find  in  birds  and  to  a  much  more  marked  extent  throughout  the  scale  of 
mammals  up  to  man  (vide  Chapter  III.).  To  the  hippocampic  formation 
(archipallium)  there  is  added,  by  progressive  development,  the  neopallium 
which  is  evolved  from  what  is  called  by  Johnston  the  somatic  area  (internal 
part  of  the  hemisphere) .  It  is  from  this  part  of  the  neopallium  that  we  have 
the  gradual  development  and  differentiation  of  the  non-hippocampic  areas 
of  the  cortex,  which  does  not  receive  fibres  directly  from  the  sensory  organs 
but  rather  from  the  centres  that  immediately  preceded  it  in  evolution — i.e. 
the  various  nuclei  of  the  optic  thalamus.  These  prepare  and  modify  the 
nerve-waves  for  the  formation  of  the  images  which  are  the  immediate  and 
necessary  components  in  the  structure  and  evolution  of  intelligence. 

Alongside  of  the  development  of  the  cerebral  cortex  we  have  a  growing 
complexity  of  the  system  of  thalamo- cortical  connections,  and  while  the 
thalamus  preserves  its  reflexes  through  the  peduncle  (from  the  medial  grey 
substance  and  the  hypo-thalamic  region)  we  have  a  gradual  development 
of  the  neothalamus  (Edinger)  which  comprises  the  anterior,  lateral,  and 
ventral  nuclei,  the  pulvinar  and  the  lateral  and  medial  geniculate  nuclei. 
In  primates  and  in  man  these  assume  great  importance  because  of  their 
relations  and  connections  with  differentiated  areas  of  the  cerebral  cortex. 


12  THE  MECHANISM  OF  THE  BRAIN 

The  neothalamus  is,  as  it  were,  the  vestibule  of  the  cerebral  cortex 
(Henrick 1) . 

Its  nuclei,  we  have  said,  are  organs  for  the  preparation  of  the  nerve- waves 
of  all  the  senses  except  smell,  which  has  its  analogous  preparatory  nucleus 
in  the  anterior  perforated  substance.  It  is  from  these  nuclei  that  the  nerve- 
waves  provoked  by  stimuli  from  the  external  world  reach  the  cerebral  cortex 
where  they  are  spiritualised  (images) .  The  exogenous  material  of  conscious- 
ness is  furnished  by  the  images. 

If  the  nuclei  of  the  optic  thalamus  are  united  with  one  another  by  means 
of  associative  paths  we  can  readily  conceive  that  they  may  give  rise  to  a 
series  of  adaptations  and  adequate  movements  (the  psychic  facts  which 
Luciani  attributes  to  the  subcortical  ganglionic  masses) . 

These  reactions  are  almost  identical  in  each  animal  species  according  to 
the  more  or  less  complex  structure  of  the  optic  thalamus,  although  it  may  not 
be  easy  to  distinguish  what  part  of  the  reactions  of  these  beings  belongs  to 
the  optic  lobes  and  what  to  the  thalamus  or  to  the  cortex  now  in  course  of 
formation. 

With  the  development  of  the  cerebral  cortex  we  have  not  only  new  cell- 
masses  superimposed  on  pre-existing  ones  but  at  the  same  time  these  become 
more  numerous,  more  complicated  in  structure  and  more  closely  associated 
with  one  another,  so  that  we  no  longer  have  the  invariability  (relative)  that 
is  characteristic  of  the  reactions  of  lower  creatures  and  all  those  reactions 
included  amongst  the  automatisms,  which  arise  mainly  from  the  subcortical 
centres.  We  have,  instead,  remarkable  variability  of  attitude  in  the  in- 
dividual and  in  the  species  proportionate  to  the  capacity  for  receiving  a 
greater  or  less  number  of  stimuli  from  the  external  world  and  for  transform- 
ing, conserving,  and  associating  these  so  as  to  give  rise  to  the  actual  notion 
which  becomes  combined  with  past  experience  (memory)  of  the  effects  of 
reactions  connected  with  previous  notions  (memory  images).  It  is  to  this 
complex  of  facts  that  we  must  attribute  the  origin  of  the  new  adaptations 
and  the  variability  of  the  movements  of  each  individual  in  the  changing 
circumstances  of  the  environment. 

The  reflexes  and  automatisms  dependent  upon  the  subcortical  centres 
become  confused  in  varying  degree  with  the  more  complicated,  variable  and 
co-ordinated  movements  that  issue  from  the  sensory  and  motor  areas  of  the 
cerebral  cortex. 

One  can  readily  understand  how  the  coming  into  play  of  this  new  cerebral 
formation,  under  the  influence  of  stimuli  much  greater  in  number  than  those 
that  succeeded  in  elaborating  the  subcortical  centres,  must  lessen,  if  not 
suppress,  the  autonomy  of  the  latter,  for  the  subcortical  centres  become 
subservient  to  the  cortex  and  transmit  their  products  to  it  for  further  trans- 
formation. The  function  of  elaboration  and  transmission,  the  substitution 
of  receptive  and  reactive  processes,  determined  by  that  sum  of  stimuli,  for 
the  thalamic  automatisms  now  transferred  to  the  cortex,  takes  away  from 

1  Henrick.  "  Some  Reflections  on  the  Origin  and  Significance  of  the  Cerebral 
Cortex."  Journal  of  Animal  Behaviour.  1913. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  13 

the  power  of  these  automatisms,  albeit  these  are  only  variable  within  very 
narrow  limits,  automatisms  in  which  is  summed  up  the  mind  of  the  lower 
vertebrates. 

The  automatisms  centred  in  the  subcortical  organs  are  not  altogether 
suppressed  although  they  are  reduced  and  under  particular  conditions  they 
exhibit  a  certain  contrast  with  the  higher  powers. 

Moreover,  the  subcortical  centres  with  their  appropriate  reflex  arcs 
(sensory-motor)  contribute  to  the  surety,  precision,  co-ordination  and  energy  * 
of  all  the  movements  brought  together  in  the  motor  area  of  the  brain  under 
the  constant  influence  of  actual  sensations  and  the  mnemonic  residua  of 
previous  sensations  and  movements  as  well  as  the  most  varied  combina- 
tions of  these.  Now,  as  the  evolution  of  the  optic  thalamus  proceeds  along- 
side that  of  the  cerebral  cortex  we  cannot  ascertain  how,  or  to  what  extent, 
the  thalamic  automatisms  develop  in  man,  because  it  is  quite  impossible  to 
distinguish  with  precision  where  the  thalamic  function  ceases  and  the  cerebral 
function  begins  and  to  what  extent  the  thalamus  contributes  to  automatic 
responses,  although  it  is  agreed  that  mental  processes  contain  a  conspicuous 
coefficient  of  automatisms  (unconscious  and  subconscious) ,  which  in  any  case 
are  of  a  much  more  complex  nature  than  the  simple  thalamic  automatisms. 

The  more  simple  structure  and  the  more  circumscribed  field  of  the  thala- 
mus as  compared  with  the  extent  and  the  varied  and  complicated  structure 
of  the  cortical  field,  furnish  a  very  reliable  anatomical  proof  of  the  great 
differences  that  exist  amongst  the  various  categories  of  products  which  by 
analogy  we  include  under  the  term  automatisms.  These,  in  the  case  of  the 
thalamus,  resolve  themselves  through  nervous  elements  and  paths  of  associa- 
tion that  are  incomparably  scantier  than  in  the  case  of  the  cortex  ;  they  come 
into  play  outside  the  field  of  consciousness,  whilst  cortical  automatisms  have 
most  often  been  effected  within  the  domain  of  consciousness  in  the  past,  under 
opportune  circumstances  come  within  it  again  and  can  be  taken  under  its 
control.  The  thalamic  automatisms  always  reveal  themselves  in  identical 
fashion  owing  to  the  structural  simplicity  of  their  anatomical  mechanisms, 
whilst  the  cortical  automatisms  undergo  variation  determined  by  the  variety 
of  stimuli  that  can  be  received  by  the  anatomical  mechanism  which  is  itself 
complex  and  variable.  The  former  are  based  upon  organic  memory,  the 
latter  derive  their  elements  from  experience  and  hence  have  as  their  basis 
psycho-organic  memory.  The  "  organic  circuit  concept  "  of  Dewey  2  is  not 
applicable  to  the  subcortical  automatisms. 

This  subject  is  discussed  in  a  succeeding  chapter.  What  is  necessary 
to  bear  in  mind,  at  this  point,  is  the  fact  that  direct  acts  of  intellect  involve 
numerous  sensory  and  motor  complexes  besides  others  of  an  unconscious  or 
automatic  order,  so  that  it  is  more  than  probable  that  the  subcortical 
mechanisms  also  come  into  play. 

There  are  those  who  hold  that  some  of  those  manifestations  that  go  to 

1  Bianchi.     "  La  emicorea  sintomatica."     Ann.  di  Nev.,  ann.  xxvii. 

2  Dewey.     "The  Reflex  Arc  Concept  in  Psychology."     Psych.  Rev.,  1893;  and 
Journ.  Philosoph.  PsychoL,  1912. 


14  THE  MECHANISM  OF  THE  BRAIN 

make  up  the  complex  phenomenology  of  the  unconscious  or  subconscious 
have  their  origin  in  the  subcortical  organs  (Herrick).  It  would  be  more 
correct  to  say  that  in  the  cycle  of  conscious  and  unconscious  cortical  re- 
actions, corresponding  with  psycho-motor  circuits,  the  automatisms  originat- 
ing from  the  subcortical  organs  play  their  part.  Here  we  have  to  deal  with 
various  circuits  superimposed  upon  and  intimately  bound  up  with  one 
another  so  as  to  constitute  a  single,  but  very  complicate,  mechanism. 

With  the  superimposition  of  new  formations  of  nervous  substance  and  the 
assumption  by  these  of  more  numerous  intercortical  and  cortico-thalamic 
relations,  or,  in  other  words,  with  the  intervention  of  a  much  greater  number 
of  nerve- elements,  the  product  is  much  more  conspicuous  and  variable  because 
it  is  the  work  not  only  of  the  part  most  recently  developed  but  also  of  pre- 
existing nervous  organs. 

This  statement  should  leave  no  room  for  doubt  because  in  every  evolu- 
tionary phase  of  the  nervous  system  we  find  this  constant  phenomenon,  that 
the  anatomical  integrity  of  pre-existing  organs  is  an  indispensable  condition 
of  the  evolution  and  functional  perfecting  of  new  nervous  organs.  In  other 
words,  the  functional  products  of  pre-existing  nervous  organs  are  indispensable 
for  the  elaboration  of  the  more  complex  products  of  work  of  the  organs  of  most 
recent  development.  If  the  earlier  products  appear  to  be  less  appreciable  it 
is  because  they  are  absorbed  as  necessary  material  in  the  production  of  the 
organ  last  evolved.  It  is  the  products  of  later  development  that  contribute 
directly  to  the  growth  of  consciousness. 


* 
*  * 


The  progressive  and  specific  functional  differentiation  of  the  cerebral 
mantle  from  its  earliest  manifestation  up  to  what  we  find  it  to  be  in  man 
proceeds  contemporaneously  from  the  general  to  the  particular,  from  the 
simple  to  the  complex.  No  true  functional  differentiation  has  yet  been 
/  detected  in  the  cortex  of  the  batrachians.  It  displays  no  well-defined  action 
upon  the  vital  functions  of  the  batrachians  and  it  may  even  be  removed 
without  any  remarkable  loss  of  activity.  Schrader  l  has  shown  that  if  the 
cerebral  hemispheres  are  removed  from  the  frog  it  loses  little  or  nothing  of 
its  ordinary  manifestations  of  life.  It  behaves  as  if  it  were  whole  and  sound. 
It  catches  insects  and  changes  its  domicile  from  land  to  water,  and  vice  versa. 
No  doubt  the  cortex  of  the  frog  is  too  simple  and  uniform  to  dethrone  the 
optic  lobes  which  are  still  the  real  higher  nervous  organs,  apart  altogether 
from  the  question  as  to  whether  or  not  it  has  commenced  to  exercise  an 
exhibiting  influence  over  certain  reflexes  (Goltz  2) . 

In  the  case  of  frogs,  the  optic  lobes  (mid-brain)  exercise  almost  the  whole 
directive  influence  over  the  life  of  these  amphibians.  They  still  enjoy  a 
good  deal  of  autonomy.  The  cortex,  now  in  course  of  formation,  presents 
no  feature  of  specific  function,  nor  does  it  seem  to  have  any  directive  influence 
over  the  subcortical  organs. 

1  Schrader.     "Zur  Physiologie  der  Froschhirn."     Pflilyer's  Archiv.,  Bd.  xli.    1887. 

2  Goltz.     Beitrdge  zur  Lehre  von  den  Nervencentren  des  Frosches.     Berlin,  1868. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  15 

When  we  come  to  birds  a  sensible  differentiation  of  the  cerebral  mantle 
has  now  made  its  appearance.  The  function  of  the  posterior  cerebral  hemi- 
sphere differs  in  some  degree  from  that  of  the  anterior  part.  Nevertheless, 
Schrader  found  that  decerebrated  birds  still  had  initiative,  were  able  to  see, 
and  wandered  about  the  room,  avoiding  obstacles. 

Complexity  of  movements  and  attitudes  is  progressive.  The  jumping 
and  swimming  of  the  frog  are  much  more  uniform  than  the  movements  of  the 
chaffinch,  and  these  again  are  much  less  complex  than  the  movements  of  the 
mouse,  dog,  elephant  and  of  the  monkey,  in  progressive  series.  And  what 
a  variety  of  attitudes  there  is  in  man  'himself  according  to  the  degree  of 
culture  attained  either  by  the  individual  or  by  the  social  group, as  the  result 

of  cerebral  development ! 

* 

*  # 

With  the  anatomical  development  of  the  cerebral  cortex  there  coincides, 
as  already  mentioned,  a  functional  differentiation.  This  can  be  demon- 
strated in  higher  mammals  by  electrical  excitation  of  the  cortical  surface 
and  by  the  effects  of  experimental  destruction  of  the  cortex.  In  the  case  of 
man,  clinical  observation  in  particular  has  contributed  to  our  knowledge. 
It  has  furnished  a  valuable  mass  of  evidence,  which,  in  the  main,  goes  to 
confirm  the  results  of  experiments  on  mammals.  AH  the  senses,  all  the 
muscular  groups,  are  represented  in  more  or  less  distinct  areas  of  the  cerebral  * 
cortex  in  apes  and  in  man. 

Functional  differentiation  and  localisation  in  the  cerebral  cortex  proceed 
in  accordance  with  that  same  law  of  evolution  that  we  meet  with  in  the  social 
life,  and  in  the  structure  of  living  things.  In  the  cortex  we  find  a  histo- 
functional  differentiation  which  reminds  us  of  the  differentiation  of  the 
nuclei  in  the  optic  thalamus  but  on  a  larger  scale  and  in  a  much  wider  sense. 

The  whole  nervous  system  of  the  more  highly  evolved  beings  is  highly' 
differentiated — e.g.  the  bundles  composing  the  spinal  medulla  differ  greatly 
from  one  another  as  regards  origin,  time  of  myelinisation  and  function.! 
There  is  differentiation  amongst  the  various  parts  that  go  to  make  up  thel 
medulla  oblongata,  the  pons,  the  cerebral  peduncle  and  the  optic  thalamus. 
The  last-named  has  a  number  of  nuclei,  as  already  mentioned,  and  these  in 
turn  are  developed  at  different  periods.1    The  same  rule  applies  also  to  the 
cerebral  cortex.     The  law  of  differentiation  and  co-operative  association    »/ 
should  be  regarded  as  fundamental.     It  corresponds  with  the  various  aspects 
of  the  energies  of  nature  assimilated  by  the  brain.     Each  of  these  develops 
its  own  appropriate  cortical  organ,  for  touch,  smell,  taste,  hearing,  sight. 

Doubts  have  been  expressed  by  some  neuropathologists  and  physiologists 
as  regards  the  doctrine  of  localisation.  No  doubt  this  is  due  to  ambiguity 
in  terms.  Some  authors  speak  of  localisation  of  intelligence  and  of  con- 
sciousness. Loeb,2  e.g.,  does  not  make  himself  perfectly  precise  and  clear 

1 V.  Bianchi.  "  Anatomische  Untersuchungen  iiber  die  Entwicklungsge- 
schichte  der  Kerne  des  Talamus  opticus  des  Kaninchens."  Monatschrift  fiir 
Psychiatrie.  Bd.  xxv. 

2  Loeb.     Physiology  oj  the,  Brain  and  Comparative  Psychology. 


16  THE  MECHANISM  OF  THE  BRAIN 

in  formulating  his  conception  of  functional  localisation  in  the  cerebral  cortex 
when  he  speaks  of  "visual  conscience"  or  of  "consciousness  of  a  limb." 
He  still  adopts  the  terms  of  Hitzig.  The  consciousness  of  a  limb  is  not 
localised,  but,  rather,  the  psychic  components — i.e.  the  memory-residua  of 
the  movements  of  the  limb — which  contribute  in  combination  with  all  other 
memories  to  the  elaboration  of  consciousness.  We  cannot  speak  of  visual 
consciousness  but  only  of  the  seat  of  actual  visual  formations  (images)  which 
are  assimilated  by  the  consciousness  or  of  the  mnemonic  traces  of  previous 
visual  perceptions,  which  have  already  become  part  of  the  mental  patrimony 

v  and  are  capable  of  being  made  use  of  for  intelligence  and  conscience.  What 
are  actually  localised  are  the  specific  and  individual  products  furnished  by 
the  work  of  the  cerebral  cortex,  distinguished  into,  areas  that  have  become 
differentiated  in  the  course  of  thousands  of  years,  under  the  influence  of 
particular  categories  of  stimuli  (manifestations  of  the  energies  of  nature). 
Whether  or  not  these  areas  have  definite  boundaries  is  a  question  of  little 
consequence.  All  of  them  furnish  components  for  the  development  of  con- 
sciousness. The  case  of  Laura  Bridgmann  does  not  support  the  view  of 
Loeb,  because,  if  a  sense  organ  and  its  respective  cortical  organ  are  awanting 
their  function  may  be  compensated  by  greater  development  of  other  senses 
and  by  a  great  associative  power  in  other  parts  of  the  brain  that  are  more 
ideveloped.  Again,  the  will  is  not  localised  although  the  motor  area  whence 
/are  discharged  the  impulses  animating  the  muscular  movements  is  specialised. 
Volitional  motor  reactions  are  the  result  of  mental  processes  which  often 

~j  involve  the  entire  brain.    Who  would  dream  of  localising  what  we  call  the 

jwill? 

Thought,  even  when  it  appears  simple,  is  always  the  effect  of  widely 
distributed  cerebral  activity.  It  is  not  localisable.  It  is  only  the  elements 
from  which  it  results  that  are  capable  of  localisation. 


* 
*  * 


The  patient  and  laborious  work  of  the  past  fifty  years  has  afforded  ample 
proof  of  the  soundness  of  the  experimental  and  clinical  basis  on  which  is 
founded  the  doctrine  of  the  localisation  of  the  functions  of  the  cerebral 
cortex.  This  is  now  understood  to  apply  not  in  an  absolute  sense  but  only 
to  the  isolated  and  differentiated  sensory  and  motor  processes.  The  precise 
limits  of  each  area  have  not  been  mapped  out,  with  the  exception,  perhaps, 
of  the  motor  area  and,  even  if  they  could  be,  there  are  good  grounds  for 
believing  that  they  may  vary  in  different  men.  Not  only  so  but  we  know 
that  each  function  is  bound  up  and  co-related  with  others.  Clinical  experi- 
ence, physiology  and,  to  some  extent,  histology,  have  now  demonstrated  the 
functional  complexity  of  the  relations  subsisting  between  each  sensory  and 
motor  area  and  all  the  others. 

One  might  almost  say  that  the  specific  waves  transmitted  by  all  the 
sense-organs  are  projected  upon  distinct  areas  of  the  cerebral  cortex.  These 
will  now  be  briefly  indicated. 

The  tactile  zone  is  represented  by  the  posterior  Rolandic  or  ascending 


EVOLUTION  OF  THE  NERVOUS  SYSTEM 


17 


parietal  convolution,  limited  in  front  by  the  Rolandic  fissure,  behind,  pre- 
sumably, by  the  interparietal  sulcus  (Fig.  1).     The  precise  limits,  above  and 


ZT 


LPI 


VP 


Fig.  1. — External  surface  of  cerebral  hemisphere 

ZT.  Tactile  zone.— LPI.  Inferior  parietal  lobule. — VP.  Visuo-psychic  area  (supposed 
anterior  limit). — SV.  Visuo-sensory  area. — ZU.  Auditory  area 

below,  in  the  superior  parietal  lobule  cannot  be  defined  on  the  basis 
either  of  experimental  research  or  of  clinical  observation.  On  the  inter- 
hemispheric  surface  the  tactile  area  extends  to  the  median  aspect  of  the  ascend- 
ing parietal  convolution  (Fig.  2).  Certain  experimental  investigations  and 


ZM 


Z.T 


Z.H.I 


2.F 


Fig.  2. — Median  aspect  of  cerebral  hemisphere 

ZT.  Tactile  zone.— ZM.  Motor  area.— ZM  I.  Intermediate  motor  area.— ZF.  Frontal  area.— 
ZPF.  Pre-frontal  area. 

clinical  observations  (Ferrier,  Starr)  would  seem  to  point  to  the  convolution 
of  the  corpus  callosum  (Fig.  3,  Ll)  and  even  the  hippocampus — i.e.  a  part 
of  the  limbic  lobe,  as  a  cortical  organ  of  tactile  sensibility. 

The  study  of  cell-structure,  as  well  as  certain  clinical  observations  which 


18 


THE  MECHANISM  OF  THE  BRAIN 


will  be  detailed  further  on  in  this  chapter,  would  point  to  the  necessity  for 
distinguishing,  in  the  ascending  parietal  convolution,  an  anterior  part  which 
would  be  tacto-sensory  and  a  posterior  part,  bordering  the  interparietal 
sulcus,  which  should  be  regarded  as  a  tacto-psychic  or  intermediate  tactile 
zone.  As  a  matter  of  fact,  the  majority  of  asteriognoses  and  apraxias  have 
been  due  to  lesions  limited  to  this  area.  It  is  beyond  the  scope  of  this  work 


CF.S 


S.P 


s.c 


C.C.I 


CF.S 


L.L 


Fig.  3 

CFS.    Superior   frontal    convolution.— SC.     Callosal    sulcus.— CM.    Calloso-marginal    sulcus.— 
SPR.     Para-Rolandic   sulcus. — SR.     Fissure  of   Rolando. — SP.     Parieto-oceipital   fissure.—  . 
CU.    Cuneus.— SC.    Calcarine  fissure.— CGI.    Inferior  calcarine   convolution.— LL.    Lingual 
lobule. — LI.    Limbic  convolution. — L2.    Inferior   linibic  convolution. — H.    Hippocampus. — 
U.  Uncus. — CC.  Corpus  callosum. — LQ.  Quadrate  lobule  or  precuneus 

to  enter  into  minute  details  regarding  the  various  functions  of  the  tactile 
area  and  the  question  as  to  whether  or  not  it  extends  forwards  on  to  the 
anterior  Rolandic  convolution,  as  Horsley  has  maintained,  on  rather  slender 
grounds,  as  we  shall  see. 

,  /  The  visual  area  comprises  the  convolutions  surrounding  the  calcarine 
fissure  (Fig.  3),  the  cuneus,  a  part  of  the  lingual  lobule,  the  external  surface 
of  the  occipital  lobe  and  almost  all  the  inferior  parietal  lobule  (Fig.  1) .  Here, 
again,  experimental  evidence,  clinical  experience  and  cytotectural  studies 
compel  us  to  distinguish  a  visuo- sensory  area  limited  to  the  convolutions  of 
the  calcarine  fissure  and  the  occipital  pole,  and  also  another  larger  area 
surrounding  the  former  and  comprising  the  remainder  of  the  cuneus,  a  part 
of  the  lingual  lobe,  the  external  surface  of  the  occipital  lobe,  and  the  inferior 
parietal  lobule.  The  last-named  is  to  be  regarded  as  the  most  evolved  in 
as  much  as  it  is  the  parietal  organ  for  reading — i.e.  for  visual  perception  of 
the  graphic  symbols  of  the  images  of  the  external  world,  formed  and  conserved 
in  their  own  particular  sensory  areas. 

The  auditory  zone  may  be  held  to  embrace  two-thirds  (middle  and 
posterior)  of  the  temporal  lobe.  Like  the  visual,  it  can  be  divided  into  three 
portions.  First,  there  is  the  fundamental  or  acoustic -sensory  area  limited 
approximately  to  the  transverse  temporal  convolution.  Next,  a  much 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  19 

larger  acoustico-psychic  area  surrounding  the  latter,  and  concerned  with 
the  formation  and  comprehension  of  the  acoustic  images  of  speech.  This 
area  is  confined  to  the  posterior  portions  of  the  first  and  second  temporal 
convolutions,  although  its  limits  are  not  precisely  defined  (ZU,  Fig.  1). 
Around  it  lies  a  third,  more  extensive,  area,  representing  a  greater  evolution 
of  language  in  its  grammatical  and  syntactical  inflexions,  allowing  the  ex- 
pression of  thought  as  a  reflex  of  history,  of  personal  and  human  experiences 
or,  again,  of  the  imagination  when  the  mind  projects  itself  into  the  future, 
following  the  laws  of  association,  on  the  basis  of  experience  (phantasy) . 

The  olfactory  and  gustatory  areas  are  unfortunately  not  so  well  defined 
but  they  are  no  doubt  less  important.  The  olfactory  area  is  situated  in  the 
olfactory  trigone  on  the  median  aspect  of  the  hemisphere  and  in  the  limbic 
lobe  (LI  and  L2,  Fig.  3)  in  both  its  anterior  portion  and  the  hippocampus 
(H).  The  gustatory  area  comprises  the  uncus  and  the  temporo-sphenoidal 
pole.  Whilst  the  limbic  lobe  is  concerned  with  the  sense  of  smell  it  has 
probably  also  to  do  with,  the  tactile  sense.  This  mingling  of  functions 
reminds  us  of  the  condition  of  the  cerebral  mantle  in  its  earliest  manifesta- 
tion when  the  senses  of  smell  and  taste  were  both  represented  in  the 
hippocampal  area. 

To  sum  up,  recent  investigations  go  to  prove  that  each  sensory  area  is 
divisible  into  two  or  three  parts,  one  of  which  prepares  material  for  the 
service  of  another.  One  we  describe  as  purely  sensory,  another  as  "psycho- 
sensory  or  intermediate.  The  latter  only  functions  when  the  former  is 
active — i.e.  when  the  area  that  preceded  it  in  the  process  of  development  is 
sound  and  whole.  Metaphorically  speaking,  the  first  area  prepares  the  raw 
material  for  transmission  to  the  factory,  where  it  is  converted  into  concrete 
images  of  the  things  (of  the  stimuli)  that  go  to  make  up  the  intellect.  In  each 
cerebral  area  we  have  a  reproduction  of  the  relations  which  subsist  between 
the  cerebral  cortex  and  the  optic  thalamus.  Take  the  case  of  the  calcarine 
area  in  its  relations  to  the  visuo-psychic  area.  We  can  put  it  thus  :  when 
the  organs  of  lower  order  suspend  operations,  work  ceases  in  higher  organs, 
even  though  they  are  in  perfect  working  order,  simply  through^ lack  of 
necessary  material.  This  law  permits  no  shadow  of  doubt.  We  have  an 
excellent  example  in  the  function  of  language,  in  the  relations  of  the  images 
of  speech  to  the  concrete  images  of  things. 

The  acoustic  images  of  speech  serve  as  the  symbol  not  only  of  the  objects 
themselves  found  in  the  external  world  but  also  of  the  visual,  tactile,  and 
other  sensory  images  of  these.  The  recall  of  the  acoustic  image  of  the  word 
pen,  e.g.,  is  subject  to  this  condition,  that  the  visual  and  tactile  images  of 
the  pen  are  available.  If  these  are  lacking,  then,  even  although  the  object 
itself  confronts  us,  the  acoustic  word  image  that  symbolises  the  object 
cannot  be  evoked  or  is  only  with  great  difficulty  recalled. 

'It  is  clear,  then,  that  localisation  is  not  to  be  understood  in  its  ordinary 
and  restricted  sense.     Rather  should  we  think  of  it  as  involving  a  continuous 
chain  of  processes,  each  having  its  own  organ  and  all  being  closely  bound  up       ^ 
with  one  another  functionally  and  anatomically.     This  is  particularly  true    ' 


20  THE  MECHANISM  OF  THE  BRAIN 

when  we  come  to  speak  of  intelligence  or,  if  you  like,  Mind,  which  is  a  func- 
tional product  of  the  whole  cerebrum.  One  must  admit  that  Munk  had  good 
reason  on  his  side  when,  in  the  course  of  his  memorable  debate  with  Hitzig, 
he  maintained  that  intelligence  had  no  circumscribed  seat  in  the  cerebral 
cortex  but  involved  the  entire  brain.  If  intelligence  emanates  from  play  of 
sensory  images  of  the  external  world  elaborated  by  the  respective  sensory 
areas,  and  of  infinite  combinations  of  these  and  other  images  not  sensory  in 
character,  it  is  very  evident  that  all  these  areas  contribute  in  varying  pro- 
portion to  the  content  and  play  of  intellect.  It  is  also  manifest  that  experi- 
mental destruction  of  one  or  more  of  these  areas  must  have  a  distinct  effect 
upon  the  intellectual  function  which  is  now  deprived  of  the  contribution 
from  the  area  or  areas  destroyed,  always  taking  into  account  the  degree  of 
cerebral  development  in  the  animal  that  is  the  subject  of  experiment.  The 
function  in  this  case  is  impoverished  because  intellect  is  the  result  of  associa- 
tion and  synthesis  of  the  simple  or  complex  images  and  representations 
furnished  by  the  respective  areas.  The  actual  amount  of  damage  will  depend 
in  some  measure  upon  the  seat,  extent  and  depth  of  the  lesion. 

Such,  then,  is  the  conception  of  the  doctrine  of  the  localisation  which  the 
data  at  our  command  warrant  us  in  accepting,  and  it  is  the  conception  which 
the  author  has  supported  for  many  years.  In  its  essential  features  it  may 
be  summed  up  in  the  functional  differentiation  of  the  cortex  into  as  many 
areas  as  there  are  special  senses.  To  these  we  must  add  not  only  the  motor 
area — which  represents  in  the  cortex,  on  a  higher  scale,  what  the  anterior 
cornu  is  in  the  spinal  medulla — but  also  those  areas  which  are  neither  sensory 
nor  motor  in  their  essential  characters,  areas  which  now  demand  special 
consideration.1 

* 
*  * 

First  of  all,  it  is  to  be  remarked  that  the  phenomena  that  go  to  make  up 
what  we  call  intelligence  are  not  co-extensive  merely  with  the  sensory  areas 
of  the  cerebral  cortex  (the  areas  already  described  as  factories  where  the 
images  are  formed  and  their  memories  stored)  and  the  excitable  motor  area. 

1  The  arguments  that  have  been  used  from  time  to  time  against  the  doctrine  of 
cortical  localisations  strike  us  as  being  a  species  of  mental  gymnastics  rather  than 
sound  views  controlled  by  experimental  findings  and  clinical  observations.  Some 
seem  to  regard  the  doctrine  of  the  localisation  of  the  functions  of  the  brain  as  still 
very  involved.  The  want  of  correspondence  between  functional  areas  and  cyto- 
tectural  areas,  the  presence  of  motor  cells  and  motor  paths  in  the  sensory  areas, 
and  the  motor  phenomena  induced  by  excitation  of  sensory  areas,  have  been 
brought  forward  as  arguments  against  the  doctrine.  So  far  as  the  want  of  corre- 
spondence between  the  areas  that  have  been  mapped  out  by  histologists  on  the 
basis  of  cell -architecture  with  those  assigned  by  experimental  and  clinical  research 
to  a  particular  function  is  concerned,  it  is  to  be  pointed  out  that  these  histologists 
have  admitted  that  it  is  necessary  to  make  certain  reservations  in  applying  the 
data  of  histology  to  physiology  and  to  clinical  findings.  The  presence  of  motor 
cells  and  paths  in  the  sensory  areas  brings  to  mind  the  old  notion  that  these  were 
sensory-motor  areas,  a  point  raised  by  the  author  in  1882.  (Riv.  Sper.  di  Fren. 
1882.) 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  21 

The  accident  wards  of  our  hospitals,  as  well  as  experimental,  morphological 
and  histological  investigations,  have  demonstrated  the  existence  of  extensive 
areas  of  the  cerebral  cortex  which  do  not  possess  sensory  characteristics  in 
the  ordinary  sense  of  the  term  nor  yet  the  features  of  motility.  The  evolu- 
tion of  the  brain,  as  manifested  throughout  the  scale  from  the  lower  mammals 
up  to  man,  has  greatly  enlarged  the  cortical  field  of  intellectual  function  by 
the  appearance  and  development,  in  apes  (primates)  and  more  particularly 


5FN 


Fig.  4 

FRl,  FR2,  FR3.  Frontal  convolutions,  superior,  middle  and  inferior.— FRA.  Ascending 
frontal  convolution. — PARA.  Ascending  parietal  convolution. — OP.  Parietal  operculum.  — 
SIP.  Interparietal  sulcus.— LPS.  Superior  parietal  lobule.— LOB,  PAR,  INF.  Inferior 
parietal  lobule. — GSM.  Supramarginal  gyrus. — CA.  Angular  gyrus,  posterior  extremity. — 
Tl,  T2,  T3.  Superior,  middle,  and  inferior  temporal  convolutions.— OC1,  OC2,  OC3. 
Superior,  middle  and  inferior  occipital  convolutions. — SFS.  Superior  frontal  sulcus. — 
SFN.  Inferior  frontal  sulcus. — BVS.  Ascending  branch  of  fissure  of  Sylvius. — PRF.  Pre- 
frontal  sulcus.— R.  Fissure  of  Rolando.— SIP.  Interparietal  sulcus.— ST1,  ST2.  Superior 
and  inferior  temporal  sulci. — S.  Fissure  of  Sylvius 

in  man,  of  cortical  regions,  the  function  of  which  is  neither  sensory  nor  motor 
in  the  ordinary  acceptation  of  the  term. 

This  fact  gave  rise  to  the  conception  of  the  existence  of  cortical  organs 
in  which  the  higher  mental  operations  take  place,  a  conception  that  has  been 
gradually  developing. 

Hitzig  advanced  the  hypothesis  in  favour  of  a  centre  of  this  nature. 
Some  time  later,  the  author,  in  the  course  of  some  experimental  investiga- 
tions, was  led  to  infer  the  existence  of  an  organ  in  which  there  takes  place 
a  confluence  of  images  re- evoked  in  other  parts  so  that  a  process  of  co- 
ordination is  arrived  at  thereby.  This  would  be  a  centre  of  centres,  giving 
rise  to  a  more  extensive  association  of  the  products  of  perception  (mnemonic 
images)  and,  consequently,  to  more  complex  mental  products  (mental 
syntheses).  Flechsig  put  forward  the  same  theory.  Subsequently  many 
others  have  admitted  the  existence  of  this  high  function,  consisting  in  the 
power  of  associating  and  combining  the  mental  products  of  the  perceptive 
areas  and  recomposing  them  into  psychic  complexes  of  a  higher  order.  At 


22  THE  MECHANISM  OF  THE  BRAIN 

the  same  time  it  is  to  be  remarked  that  all  are  not  agreed  as  to  the  precise 
cortical  region  that  is  to  be  regarded  as  the  seat  of  this  very  superior  function 
nor  as  to  the  exact  mechanism  concerned  therein.  Some  authors  (Hitzig, 
Bianchi)  regard  the  frontal  lobe  as  the  centre  of  this  association  and  co- 
1  ordination  ;  others  have  located  it  in  the  so-called  posterior  associative 
«  centre  or  parieto-temporo- occipital  region  of  Flechsig.1  The  latter  view  is 
supported  by  not  a  few  physiologists  and  psychiatrists.  At  the  same  time, 
Flechsig' s  doctrine  has  met  with  a  strong  and  consistent  opposition  on  the 
part  of  many  neurologists  and  it  has  been  warmly  contested  in  almost  all 
the  discussions  that  have  taken  place  on  this  subject  on  the  occasion  of 
International  Congresses. 

Before  proceeding  to  discuss  the  thesis  which  I  desire  particularly  to 
put  forward  as  regards  the  function  of  the  frontal  lobes,  it  will  be  well  to 
clear  the  ground  by  giving  a  rapid  review  and  criticism  of  the  ponderous 
doctrine  of  Flechsig  and  the  anatomical  basis  on  which  it  is  founded. 

The  idea  of  the  existence  of  associative  areas  or  zones  of  co-ordination 
had  already  been  clearly  expressed  by  me  in  1883  as  the  following  quotation 
from  my  work  dealing  with  experimental  investigations  into  the  functional 
compensations  occurring  in  the  cerebral  cortex  shows  2 : — 

"  Sight,  regarded  as  the  perception  and  cognition  of  objects  falling  within 
the  visual  field,  is  not  to  be  considered  as  the  result  of  a  physiological  process 
of  a  simple  nature  nor  of  processes  that  merely  follow  one  another  in  time 
and  space.  Rather  is  it  to  be  regarded  as  the  complex  and  co-ordinated 
result  of  several  processes,  varying  in  nature,  following  one  upon  another 
and  extended  over  the  cerebral  surface.  Perception  of  an  object,  in  order 
to  furnish  data  for  its  cognition,  requires  :  (1)  a  luminous  stimulus  ;  (2)  a 
series  of  ocular  movements  the  effecting  of  which  delineates,  as  it  were,  in 
the  corresponding  perceptive  centre,  the  features  of  form,  extension  and 
spatial  relations  ;  (3)  the  co-ordination  of  these  two  factors,  bringing  about 
objective  unity  and  giving  rise  to  the  image  of  the  object  in  the  perceptive 
centre.  If  there  is  no  morphological  difference  between  the  elements  con- 
cerned in  these  various  physiological  moments  of  vision,  no  one  will  yet  care 
to  deny  that  these  elementary  facts  differ  in  nature  from  one  another  and  may 
accordingly  be  manifested  in  different  nervous  elements  and  in  different  sites. 
Electric  stimulation  of  different  portions  of  the  extensive  visual  area  of  the 
dog  affords  evidence  of  the  differentiation  of  its  component  parts.  In  fact 
the  anterior  portion  of  the  second  external  convolution  (excitation  of  which 
is  followed  by  contraction  of  the  orbicularis  palpebrarum)  shows  close 
relations  with  intensities  of  luminous  impressions  as  such  and  may  be  re- 
garded as  the  field  of  light  and  colour  impressions.3  The  central  and  most 

1  Flechsig.     Die  Localisation  der  Geistigen  Vorgange,  etc.     Leipzig,  1896. 

2  Bianchi.     La  Psichiatria,  la  N europatologia  et  le  scienze  affini.     1883. 

3  The  author  was  induced  to  regard  the  anterior  part  of  the  visual  zone  as  a 
luminous  centre  because  of  the  spasmodic  movements  of  the  orbicularis  palpebrarum 
which  he  looked  upon  as  light-reflexes,  but  he  would  not  maintain  that  view  to-day. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  23 

prominent  part,  electric  excitation  of  which  produces  bilateral  and  co- 
ordinated movements  of  the  ocular  bulbs,  is  the  site  of  formation  and  registra- 
tion of  the  features  of  form,  size  and  spatial  relations  of  the  object,  for  these 
depend  upon  movements  of  the  ocular  muscles.  The  occipital  lobe  does 
not  respond  to  electric  stimulation  but  extirpation  in  mammals  (dogs)  is 
followed  by  the  same  symptoms  as  are  produced  by  extirpation  of  one  of  the 
afore-mentioned  sections.  Its  function  is  to  co-ordinate  the  two  more 
elementary  factors  of  visual  perception,  thus  completing  the  image  of  the 
object." 

The  results  of  the  author's  investigations,  even  at  that  date,  induced  him 
to  affirm  the  existence  of  an  area  for  the  co-ordination  of  the  elements  of 
visual  perception,  and  there  seemed  to  be  good  grounds  for  believing  that 
the  same  thing  held  good  in  the  case  of  the  other  sense-perceptions.  The 
term  "  area  of  co-ordination  "  was  only  another  way  of  expressing  what  is 
now  more  generally  known  as  "  association  area." 

Since  that  date  this  additional  fact  has  been  brought  to  light — that  the 
sensory  fields  are  rather  extensive  and  their  limits  ill- denned.  All  functions 
referable  originally  to  the  same  sense  should  be  regarded  as  being  comprised 
within  the  same  sensory  field  for  they  represent  grades  of  evolution  or  sub- 
sidiary functions  closely  bound  up  with  the  primitive  formation  of  the  special 
images  referable  to  that  particular  sense. 

On  the  basis  of  clinical  observations,  and  apparently  also  of  cortical 
histology,  one  can  formulate  the  general  law  that  as  each  sensory  area 
evolves  it  assumes  different  histological  characters  and  furnishes  products 
of  higher  value  for  the  development  of  intellect.  The  old  conception  of 
evolutionary  areas,  formulated  by  the  author  many  years  ago,  has  been 
confirmed  by  later  clinical  and  histological  researches,  and  this  is  true  as 
regards  both  the  sensory  spheres,  which  especially  have  been  the  objects 
of  investigation,  and  also  the  motor  spheres.  An  outstanding  example  is 
furnished  by  the  development  of  our  knowledge  regarding  the  visual  zone. 

Amongst  the  clinical  investigations  that  have  rendered  valuable  con- 
tributions to  the  physiological  and  clinical  doctrine  of  the  cerebral  localisa- 
tions the  numerous  and  convincing  researches  of  Henschen,1  and  those  of 
Vialet,  are  especially  worthy  of  notice,  for  on  them  was  based  and  formulated 
the  doctrine,  fully  confirmed  by  subsequent  clinical  researches,  that  in  the  y 
human  brain  the  cortical  visual  area  is  represented  by  the  convolutions 
bordering  upon  the  calcarine  fissure  and  by  the  occipital  pole.  This  area 
is  the  field  of  cortical  perception  of  luminous  retinal  impressions.  Anatomical 
observations  support  this  hypothesis.  In  point  of  fact  the  fibres  of  the  optic 
tract,  after  being  interrupted  in  the  optic  thalamus  (in  the  external  geniculate 
body  and  the  pulvinar)  proceed  onward  again  as  the  "  bundle  of  Gratiolet  " 
or  thalamo- cortical  bundle,  and  terminate  precisely  in  those  convolutions 
forming  the  lips  of  the  calcarine  fissure  and  in  the  occipital  pole.  This  area 

1  Henschen.  Die  Pathologie  des  Gehirns,  vol.  ii.,  1892 ;  also  Klinische  und 
anatomische  Beitrdge  zilr  Pathologie  des  Gehirns.  Upsala,  1911. 


24  THE  MECHANISM  OF  THE  BEAIN 

represents  the  projection  of  the  retina  upon  the  cerebral  mantle  and  can  be 
divided  into  sectors  corresponding  to  the  sectors  of  the  retina,  always  taking 
into  account  the  refraction  of  the  luminous  rays.  Such  was  the  doctrine 
advanced  by  Henschen.  It  has  been  confirmed  by  many  others,  including 
Pierre  Marie,1  who  recently  examined  a  number  of  soldiers  wounded  in  the 
occipital  lobe  and  found  that  the  visual  field  showed  blind  sectors  with  the 
characters  of  hemianopsia,  whenever  the  injury  fell  within  the  limits  of  the 
zone  of  cortical  projection  of  the  retina. 

The  old  ideas  expressed  by  the  author  have  been  amply  confirmed  by 
the  later  clinical,  experimental  and  histological  researches,  for  all  now  agree 
that  the  visual  area  is  not  strictly  limited  to  the  region  of  the  calcarine  fissure 
and  the  occipital  pole.  Another  more  extensive  region  has  been  gradually 
formed  around  the  former.  It  has  been  named  by  Campbell  the  visuo- 
psychic  zone  so  as  to  distinguish  it  from  the  other,  the  visuo- sensory •.  It  is 
in  the  visuo-psychic  zone  that  the  concrete  visual  images  are  formed  with 
the  concurrence  of  the  essential  and  necessary  products  furnished  by  the 
visuo-sensory  calcarine  area.  If  the  latter  is  destroyed  we  get  blindness  of 
the  visual  field  of  the  retina  as  represented  in  its  various  sectors  or  quadrants. 
It  is  evident,  then,  that  this  area  plays  an  essential  part  in  the  visual  function 
because  the  element  of  light  is  a  component  sine  qua  non  of  the  visual 
function  (perception),  but  it  is  not  the  only  anatomical  field  concerned  with 
perception.  The  images  are  formed  in  the  peri- calcarine  area,  and  on  the 
external  aspect  of  the  occipital  lobe,  and  perhaps  also  in  the  parietal  lobe, 
as  will  afterwards  be  seen.  There  are  other  components  that  must  be  com- 
bined with  the  element  light  so  as  to  permit  the  formation  of  the  visual 
images  (on  the  external  aspect  of  the  parieto- occipital  lobe).  I  refer  to  the 
motor  components.  It  is  the  fusion  of  these  with  the  luminous  elements 
that  gives  rise  to  the  concrete  visual  image.  Clinical  and  experimental 
data  find  support  in  the  facts  of  anatomy,  for  the  lips  of  the  calcarine  fissure 
are  connected  wth  the  external  surface  of  the  occipital  lobe  and  with  the 
inferior  parietal  lobule  by  means  of  certain  well-recognised  bundles  of  fibres. 
I  refer  particularly  to  Wernicke's  vertical  occipital  bundle,  Yialet's  transverse 
bundle  of  the  lingual  lobule,  and  the  transverse  bundle  of  the  cuneus.2 

The  statement  made  by  some  physiologists  that  the  images  are  formed 
in  one  cortical  field  and  conserved  in  another  from  which  they  can  then  be 
evoked  is  no  doubt  ambiguous  but  it  is  not  without  foundation,  for  the 
primary  sensory  zones,  such  as  the  calcarine  and  other  analogous  areas, 
are  not  the  fields  of  formation  of  concrete  images  of  the  external  world  and  of 
spatial  relations.  They  merely  furnish  some  essential  elements  which  have 
to  be  combined  with  the  motor  components  before  they  can  give  rise  to  the 
concrete  image.  Destruction  of  the  primary  area — e.g.  the  calcarine — causes 
complete  blindness.  Destruction  of  the  secondary  area  spares  luminous 
perception,  to  some  extent,  but  destroys  the  capacity  for  perception  and 
recognition  of  objects  (Munk's  psychic  blindness).  Regarded  in  this  light, 
it  is  clear  that  a  perceptive  zone  is  necessarily  an  associative  zone.  The 
1  Pierre  Marie,  Revue  Neurologique.  1916,  2Dejerine,  Anat,descentresnerveux,  Vol,  i. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  25 

combining  of  different  elements  so  as  to  give  rise  to  visual  images  becomes 
more  evident  when  we  trace  the  development  of  sight  in  the  infant. 

In  the  first  days  after  birth,  the  infant  perceives  only  the  light,  not  the 
form  of  objects,  nor  distance,  nor  spatial  relations.  It  is  only  later  that  it 
perceives  these  other  features,  as  it  commences  to  measure  distances  and  to 
form  its  first  notions  of  space.  The  researches  of  Brodmann,  Campbell  and 
Bolton  have  demonstrated  the  fact  that  the  visuo-psychic  zone  is  developed 
at  a  later  period  than  the  visuo-sensory  area  and  presents  marked  differences 
in  structure  as  compared  with  the  latter. 

All  that  has  been  said  above  with  regard  to  the  visual  images  is  equally 
applicable  to  the  other  senses. 

Flechsig  in  several  of  his  publications  has  expressed  practically  the  same 
idea  in  another  form.  He  asserts  that  around  the  projection  zones,  properly 
so  called,  there  are  formed  intermediate  zones  which  would  not  really  be 
associative  areas  in  the  strict  sense  of  the  term,  but  centres  of  secondary 
sensibility  as  distinguished  from  the  centres  of  primary  sensibility.1  They 
would  contain  a  smaller  number  of  projection  fibres  than  the  primary  centres 
and  a  greater  number  than  the  terminal  zones.  It  thus  appears  that  Flechsig 
has  now  reduced  the  extent  of  his  association  centres  to  almost  a  third  of 
that  ascribed  to  them  in  his  original  publication,  whilst,  at  the  same  time, 
the  field  of  the  centres  of  sensibility  is  correspondingly  increased. 

The  first  areas,  those  of  primary  sensibility,  are  projection  areas  of  a 
receptive  order  ;  the  second- — i.e.  Flechsig's  centres  of  secondary  sensibility — 
may  be  more  appropriately  described  as  perceptive.  The  fibres  received  by 
the  latter  get  their  myeline  sheaths  some  time  after  the  fibres  of  the  first 
system  and  in  a  progressive  manner  from  the  periphery  of  the  receptive 
zones  towards  the  terminal  zones,  which  is  the  name  Flechsig  gives  to  the 
outermost  areas  of  the  centres  of  secondary  sensibility.  The  nerve-fibres 
that  are  late  in  becoming  myelinised  come  for  the  most  part  from  the  re- 
ceptive areas,  so  that  it  seems  a  very  likely  inference  that  in  the  so-called 
associative  areas  we  have  an  elaboration  of  the  products  of  work  of  the 
receptive  projection  areas. 


* 

*  * 


According  to  Flechsig  2  there  are  three  associative  areas  on  the  external 
surface  of  the  hemisphere  ;  an  anterior  or  frontal  situated  in  front  of  the 
motor  or,  as  he  calls  it,  the  somaesthetic  or  tactile  zone  ;  a  much  smaller 
middle  area  consisting  of  the  insula  situated  between  the  frontal  lobe,  the 
olfactory,  somaesthetic  and  auditory  areas  ;  a  third,  considerably  larger 
than  the  two  preceding,  the  great  posterior  or  parieto-temporo- occipital 

1  To  avoid  academic  discussion  dependent  upon  variation  in  terms,  it  is  well  to 
mention   that    Flechsig's   centre   of   secondary  sensibility  corresponds   to   the   per- 
ceptive zone,  such  as  the  previously  mentioned  visuo-psychic  and  acoustico-psychic 
areas,  and  to  the  author's  "  field  of  co-ordination  of  the  components  of  the  concrete 
images  "  as  conceived  in  1883.     LOG.  cit. 

2  Flechsig.     Die  Localisation  der  geistigen  Vorgdnge.     Leipzig,  1896. 


26 


THE  MECHANISM  OF  THE  BRAIN 


associative  zone  which  includes  a  wide  surface  limited  in  front  by  the  post- 
rolandic  convolution  and  the  interparietal  sulcus,  in  front  and  below  by  the 
insula,  the  olfactory  zone  (according  to  some  also  acoustic)  and  the  auditory 


u  </) 

O  C/3 
0< 


area,  behind  by  the  optic  zone.     It  is  continued  on  to  the  inferior  aspect 
of  the  hemisphere  as  far  as  the  hippocampus  (Figs.  5  and  6). 

In  a  later  publication  Flechsig,1  as  the  result  of  further  investigations,  has 
described  a  much  larger  number  of  special  areas  called  by  him  embryological 
cortical  territories.  Of  these  he  distinguished  forty  (Figs.  7  and  8)  and  this 
number  was  not  necessarily  final.  This  large  number  of  cortical  territories 

1  Flechsig.       Neue    Untersuchungen  iiber  die  Markbildung  in   dem  menschlichen 
Grosshirnlappen.    1898. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM 


27 


is  divided  into  three  groups  :  (a)  primordial  territories  which  normally  are 
formed  before  the  foetus  reaches  maturity  (Nos.  1  to  8  in  his  system)  and 
correspond  to  genuine  projection  zones  ;  (6)  intermediate  territories  the  fibres 


of  which  get  their  myeline  sheaths  up  to  one  month  after  birth  at  full  time 
(Nos.  9  to  32)  ;  these  areas  are  situated  in  the  immediate  vicinity  of  the  pro- 
jection zones  ;  (c)  terminal  territories  the  fibres  of  which  mature  from  one 
to  four  months  after  birth  at  full  time  (Nos.  33  to  40) .  In  a  subsequent 
communication  to  the  International  Congress  of  Physiologists  held  at  Turin, 
Mechsig  reduced  the  number  of  these  areas  from  forty  to  thirty-six,  as  the 
result,  he  said,  of  further  investigations. 


28  THE  MECHANISM  OF  THE  BRAIN 

At  the  International  Congress  of  Psychology  held  in  Rome,  1905,1  he 


Fig.  7 

spoke  of  thirty-five  areas  and  expressed  his  agreement  with   the  views 
the  author  put  forward  at  the  Congress  in  Madrid,2  1903,  concerning  the 


2Sa 


Fig.  8 
intellectual  value  of  the  language  zones,  and  thus  detracted,  to  some  extent, 

1  Flechsig.     "  Hirnphysiologie    und    Willentheorien."      Atti    del    Congresso    In- 
ternazionale  di  Psicologia.     Rome,  1905. 

2  Bianchi.     XI  Ve  Congres  International  de  Medecine.     Madrid,  1903. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  29 

from  the  importance  he  originally  ascribed  to  the  posterior  associative  zone, 
giving  instead,  to  language  and  the  cortical  area  of  speech  the  value  the 
author  had  assigned  to  it  in  the  intellectual  mechanism,  as  long  ago  as 
1887. ! 

A  problem  of  anatomy  and  psychology  so  important  as  this,  considered 
without  prejudice,  cannot  be  solved  solely  by  histological  inquiries  such  as 
those  of  Flechsig  because  it  is  proven  that  myelinisation  of  the  endo- 
hemispheric  fibres  does  not  follow  a  constant  law,  and  even  if  it  did,  it  could 
not  be  inferred,  as  a  corollary  without  exception,  that  this  geography  of  evolu- 
tionary anatomy  should  be  regarded  as  a  sure  foundation  for  a  species  of 
psychological  geography.  Even  granting  it  were  true,  there  would  still  be 
no  difficulty  in  accepting  the  author's  view,  for  the  intermediate  and  terminal 
territories  would  fall  to  be  regarded  as  fields  of  extension  of  the  receptive 
and  perceptive  functions  of  the  corresponding  primordial  territories  and 
would  represent  evolutionary  phases  of  the  original  functions. 

Siemerling,  Monsieur  and  Madame  Vogt  have  shown  that  the  various 
systems  are  not  developed  in  their  entirety  at  one  and  the  same  time.  Both 
in  the  projection  and  in  the  association  territories  there  remain  undeveloped 
areas  that  have  anatomical  relations  with  one  another,  where  myelinisation 
does  not  follow  a  constant  law  of  development.  According  to  0.  Vogt,2  the 
fields  of  myelinisation  do  not  exhibit  the  same  boundaries  in  different  subjects 
nor  do  they  coincide  with  the  cyto-tectural  areas.  It  is  more  likely  that  they 
correspond  with  the  various  subcortical  nuclei,  especially  those  of  the  optic 
thalamus.  The  myelinisation  or,  in  other  words,  the  development  of  the 
fibres  of  different  sections  of  the  cerebral  mantle,  traced  from  the  fourth 
month  of  foetal  life  until  complete  development,  after  birth,  shows  no  great 
difference  between  the  frontal,  parietal  (Balkensegment)  and  parieto- occipital 
segments.  Expressed  in  figures,  the  relative  degrees  of  myelinisation  in 
these  segments  would  be  20  to  25  per  cent,  in  the  frontal  lobe,  40  to  46 
per  cent,  in  the  parietal  (Rolandic)  segment,  and  29  to  38  per  cent,  in  the 
parieto -occipital  segment. 

Dejerine  and  Monakow,  following  the  method  of  descending  degenera- 
tions, arrived  at  results  that  do  not  support  the  assertions  of  Flechsig.3 

If  we  follow  the  inductive  method  of  reasoning  we  are  obliged  to  conclude 
that  myelinisation  of  the  fibres  leading  to  the  so-called  associative  centres 
has  nothing  to  do  with  the  evolution  of  intelligence,  for  the  simple  reason 
that  whilst  the  fibres  of  the  terminal  territories  are  developed  in  the  fourth 
and  often  as  late  as  the  tenth  month  after  birth,  intelligence  is  not  developed 
until  a  much  later  period.  There  is  no  correspondence  between  the  develop- 
ment of  mental  phenomena  and  that  of  the  anatomical  territories  assigned 

1  Bianchi.     "  Un  caso  di  sordita  verbale,"  ecc.     Rivista  Sperim.  di  Freniatra. 
1887. 

2  Vogt.     Myelinisation  des  Hemispheres  Cerebraux.     Paris,  1900.     Also  O.  &  C. 
Vogt.     <l  Markreifung  des  Kindergehirns."     Neurol.  Arbeitens,  etc.     Jena,  1904. 

3  Hitzig.     "  Les     centres     de    projection    et    les    centres    d' association."      Le 
Nevraxe.     1900. 


30  THE  MECHANISM  OF  THE  BKAIN 

to  them.  The  histological  factor,  as  Brodmann  has  remarked,  remains  to 
some  extent  detached  from  the  psychological  factor  and  does  not  offer  a 
satisfactory  explanation  of  the  latter.  Flechsig  sets  out  from  an  anatomo- 
psychological  point  of  view  that  is  open  to  discussion  when  he  holds  that  the 
memory -centres  are  distinct  from  those  of  perception.  He  expresses  his 
view  in  these  words  :  "  The  spheres  of  sensibility  are,  according  to  the  degree 
of  their  connections  with  the  organs  of  the  senses,  so  many  centres  of  per- 
ception, so  that  it  is  in  them  that  one  should  seek  for  the  essential  bases  of 
the  conceptions  of  time  or  of  space.  Vice  versa  they  appear  to  be  incapable 
of  reproducing  in  an  independent  manner  large  numbers  of  images  and 
memories."  1 

Speaking  of  tactile  sensibility  he  states  that  the  corresponding  cortical 
sphere  serves  to  a  large  extent  as  the  medium  of  our  relations  with  the  external 
world  ;  that  paralysis  of  touch,  caused  by  a  lesion  of  this  sphere,  would  not 
depend  upon  loss  of  memory- images  but  upon  the  impossibility  of  associating, 
in  the  cortex,  the  tactile  impressions,  and  that  this  then  betrays  itself  in  loss 
of  the  faculty  of  co-ordination.  Practically  speaking,  Flechsig  regards  the 
association  centre  as  having  the  task  of  associating  and  reproducing  the  states 
of  excitation  of  the  different  spheres  of  sensibility,  connecting  these  spheres 
indirectly  with  one  another  by  systems  of  association-fibres.  Nevertheless,  it  is 
not  proven  nor  is  it  probable  that  there  exist  separate  centres  of  memory 
around  the  centres  of  perception.  If  we  admit  the  identity  of  the  anatomical 
substratum  of  the  perceptions  and  the  memory-records  of  sensations,  repre- 
senting the  stimuli  that  have  excited  our  senses,  we  must  also  admit  that 
the  zone  of  perception  is  at  the  same  time  the  area  of  memory.  Flechsig' s 
diction  is  very  obscure.  To  the  author's  mind  the  only  intelligent  con- 
ception of  the  psychological  mechanism  is  that  which  he  himself  has  put 
forward  since  1883 — viz.  that  perception  is  a  process  of  association  of  the 
various  components  whence  it  results.  The  product  of  perception  (the 
concrete  image  of  things)  arises  from  the  physiological  fusion  of  sensory  and 
motor  elements  furnished  by  separate  portions  of  the  same  sensory  area 
considered  in  its  entirety.  It  is  evident  that  in  the  attempt  at  interpretation 
the  receptive  has  been  confused  with  the  perceptive  area.  Destruction  of  a 
cerebral  area,  if  it  suppresses  one  of  the  components  of  the  image  which 
perception  should  furnish  or  if  it  prevents  its  physiological  fusion  with  others, 
leads  to  suppression  of  the  perceptive  process  ;  but  the  fact  remains,  beyond 
dispute,  that  we  can  still  have  reproduction  of  the  particular  images  already 
stored  in  each  normal  perceptive  area. 

If  a  so-called  association-area  were  located  in  the  occipito-parietal  zone, 
in  front  of  the  area  of  the  visual  perceptions,  keeping  in  mind  Flechsig's 
idea  that  the  association  area  is  the  intermedium  which  permits  the  process 
of  recognition  and  localisation  of  the  perceptions,  which  in  the  first  instance 
are  furnished  by  the  sensory  areas,  and  if  in  this  zone  there  should  meet 
together  not  only  the  products  of  visual  perceptions  but  in  addition  the 

Flechsig.  "  Gehirn  und  Seele,"  1896;  and  "Localisation,"  etc.  Neurol 
Centralb.  1898. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  31 

auditory,  olfactory  and  tactile  memory- images,  so  as  to  give  rise  to  series 
of  psychic  compounds  of  a  higher  order,  no  doubt  Flechsig's  hypothesis 
regarding  such  a  zone  would  be  at  once  more  probable  and  intelligible.  Yet 
this  vast  cerebral  area  fulfils  functions  that  are  undoubtedly  visual  in  char- 
acter in  its  parieto- occipital  portion  and  auditory  in  the  temporal  part. 
In  several  points  of  the  occipito-parietal  region  electrical  stimulation  is 
followed  by  ocular  movements.  Total  or  partial  destruction  of  the  said  area, 
if  it  affects  only  the  cortex,  gives  rise  to  fleeting  disturbances  of  vision  and 
nothing  more.  If  the  destruction  is  deep  we  have  permanent  hemianopsia 
and,  if  it  is  bilateral,  psychic  blindness,  in  which  case  objects  are  seen  but 
not  recognised.  The  results  of  the  writer's  investigations  are  in  close  agree- 
ment with  those  of  Munk,  Ferrier,  Luciani  and  Tamburini,  Hitzig,  Ferrier 
and  Yeo,  Horsley,  and  others,  and  show  that  after  destruction  of  the  cortex 
of  the  occipital  lobe  the  conditions  necessary  for  the  formation  and  registra- 
tion of  new  images  of  objects  seen  for  the  first  time  also  disappear,  whilst 
auditory  and  tactile  perceptions  and  memories  remain  normal. 

The  anterior  extremity  of  the  occipito-parietal  zone  in  man  also  performs 
a  function  that  is  exclusively  and  essentially  visual,  though  on  a  higher  level 
in  the  psychological  hierarchy,  for  it  is  concerned  with  reading,  in  which 
process  we  have  the  formation  and  conservation  of  the  visual  images  of  the 
graphic  signs  of  words.  From  a  psychological  point  of  view,  the  area  of 
the  graphic  visual  images  is  more  complex  and  represents  a  higher  grade  of 
evolution  than  that  of  the  visual  images  of  the  objects  themselves.  It  must 
receive  a  greater  number  of  associative  fibres  and  it  has  a  higher  physio- 
logical value  because  the  function  of  reading  is  much  more  complex  without 
ceasing  to  be  at  the  same  time  perceptive  and  visual  in  nature. 

It  thus  appears  that  the  visual  function  is  evolved  from  the  simple  lumin- 
ous perception,  with  its  seat  in  the  calcarine  fissure,  a  part  of  the  cuneus, 
and  the  occipital  pole  (Figs.  2  and  3),  by  the  addition  in  the  first  instance 
of  oculo-motor  elements,  these  giving  rise  to  the  formation  of  the  concrete 
visual  images  of  objects  (the  dotted  area  on  the  external  occipito-parietal 
area,  Fig.  1,  VP).  Having  attained  this  stage,  in  itself  rather  complex, 
it  passes  by  further  evolution  of  another  part  of  the  same  visual  area  to  the 
formation  of  the  visual  graphic  signs  of  the  objects  themselves  and  their 
sensory  images.  This  portion  of  the  visual  area  is  developed  towards  the 
anterior  limits  of  the  said  area  (Fig.  1,  LPI,  area  covered  with  small  circles). 
Bilateral  lesions  of  the  occipital  cortex,  besides  producing  a  more  or  less 
severe  psychic  blindness,  give  rise  to  a  variety  of  dementia  which  can  reason- 
ably be  regarded  as  resulting  from  the  loss  of  a  great  part  of  a  man's  in- 
tellectual capital — viz.  his  store  of  visual  images  of  the  external  world, 
for  these  form  a  considerable  proportion  of  the  sensory  elements  that 
contribute  to  the  structure  and  manifestation  of  intellect. 

A  good  deal  of  value  has  been  attached  to  Flechsig's  doctrine  in  the  field 
of  psychiatry,  for  various  forms  of  dementia  have  been  attributed  to  ana- 
tomical lesions  of  his  posterior  associative  zone.  As  a  matter  of  fact,  state- 
ments of  this  kind  have  not  been  properly  controlled  or  confirmed  by  accurate 


32  THE  MECHANISM  OF  THE  BRAIN 

neurological  and  neuro- pathological  investigations.  The  observations  that 
are  most  likely  to  help  us  in  settling  this  question  are  those  that  have  been 
made  on  the  zone  of  language.  We  know  that  word-deafness,  which  is 
generally  due  to  a  destructive  focus  in  the  posterior  portions  of  the  left 
superior  and  middle  temporal  convolutions,  causes  a  particular  variety  of 
dementia.  We  know,  too,  that  this  part  of  the  language- area  is  comprised 
within  the  limits  of  the  auditory  sensory  area  or  perceptive  area  of  Flechsig 
(intermediate  territory  No.  23,  Fig.  7).  We  all  understand  what  psychic 
and  sensory  elements  come  into  play  in  the  formation  and  comprehension 
of  auditory  word  images.  These,  in  fact,  synthetise  not  only  the  auditory 
and  kinaesthetic  elements  of  speech  but  also  the  numerous  and  complex 
series  of  visual,  tactile,  olfactory,  muscular,  etc.  images  formed  by  all  the 
other  sensory  areas,  inasmuch  as  these  images,  which  reproduce  the  external 
world,  are  expressed  in  words  which  reconstitute  in  the  form  of  phonetic 
symbols  the  objects  recognised  and  their  relations,  rendering  them  sensible 
in  all  their  details  and  all  their  qualities  as  furnished  by  the  different  senses. 
To  the  author's  mind  there  are  few  regions  of  the  cerebral  cortex  that  com- 
pare with  the  left  superior  temporal  convolution  in  its  numerous  and  ex- 
tensive relations  with  the  rest  of  the  brain,  relations  very  intimately  bound 
up  with  thought  and  all  the  psychic  manifestations.  It  is  in  this  region 
that  ideas  assume  the  plastic  form  of  speech,  which  is  ever  tending  to  give 
fuller  expression  to  their  essential  characters  and  all  the  changes  they  undergo 
in  consequence  of  an  infinite  and  perpetual  succession  of  external  and 
internal  stimuli.  Flechsig  regarded  the  auditory  area  of  speech  as  a 
"primordial"  and  "intermediate"  zone  of  perception,  and  hence  assigned 
to  it  a  less  importance  than  that  attributed  to  his  great  occipito- parietal 
zone.  The  fact  remains  that  a  small  destructive  focus  in  this  area  destroys 
the  mnemonic  capital  of  speech.  At  the  same  time  it  is  to  be  noted  that 
Flechsig  has  gradually  altered  his  opinion,  as  is  evident  from  his  communica- 
tion to  the  International  Congress  of  Psychology  in  Rome,  in  1905. 

For  many  years  the  writer  has  attempted  to  define  the  syndromes  of 
the  different  functional  areas  of  the  human  cerebral  cortex,  and  his  investiga- 
tions may  serve  to  throw  some  light  on  this  fundamental  question. 


Let  us  turn  our  attention  first  of  all  to  the  inferior  parietal  lobule,  a  part 
of  the  great  posterior  associative  zone  of  Flechsig. 

Symptoms  due  to  lesions  of  the  parietal  lobe  have  been  recorded  by 
various  writers.  They  have  been  described,  though  incompletely,  by 
Monakow.1  They  are  outlined  in  various  descriptions  of  the  optic  variety 
of  sensory  aphasia  (word-blindness),  and  Beduschi,2  in  particular,  has 
collected  the  scattered  records  in  a  monograph.  Up  till  1909,  when  the 
author  published  his  views  on  the  subject,3  there  was  no  work  that  embraced 

1  Monakow.     Gehirnkrankheiten.     1905. 

2  Beduschi.     Afasie.     Milan,  1909. 

3  Bianchi.     "  La  sindrome  parietale."     Ann.  di  Neural.     1910. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  33 

the  entire  symptomatology  of  lesions  of  the  parietal  lobe  and  provided  a 
feasible  conception  of  the  physiology  and  pathology  of  this  part  of  the 
brain. 

Human  pathology  offers  the  one  and  only  means  of  control  over  physio- 
logical doctrines  of  the  nervous  system  founded  on  experiments  and  histo- 
logical  investigations.  It  is  the  only  means  of  adjusting  these  and  bringing 
them  to  their  proper  level.  The  difference  between  lesions  of  the  parietal 
lobe  and  those  of  the  motor  area  or  the  area  of  general  sensibility  lies  in  this. 
Motor  and  sensory  paralysis  of  one  side  or  of  a  limb  is  a  fact  that  is  not 
only  quickly  noticed  by  the  patient  but  also  falls  readily  under  the  im- 
mediate observation  of  the  neuropathologist,  and  from  ancient  times  has 
claimed  the  attention  of  the  clinician  and  even  of  the  layman.  These 
paralyses  being  very  frequent  have  been  more  thoroughly  examined,  dis- 
tinguished and  classified  and  it  has  been  possible  to  establish  definite  relations 
between  the  symptoms  and  the  lesions. 

It  is  only  within  comparatively  recent  times  that  the  parietal  lobe  has 
received  much  attention,  and  lesions  therein  are  not  recognised  unless  the 
clinical  examination  is  particularly  directed  to  the  investigation  of  the 
special  symptomatic  complexes  involved,  which  are  sometimes  very  vague. 
The  physiology  and  pathology  of  this  cortical  area  are  so  ill  defined  that 
only  a  very  accurate,  acute  and  detailed  investigation  will  be  of  much 
service  in  the  advancement  of  our  knowledge  of  this  part  of  the  physio- 
pathology  of  the  brain. 

In  this  connection  it  is  to  be  observed  that  the  results  of  experiments 
upon  animals  cannot  be  presumed  to  be  applicable  to  man.  There  are 
many  facts  that  are  referable  only  to  the  human  being,  and  it  is  those  that 
must  be  singled  out  and  carefully  investigated  both  in  the  living  subject  and 
in  the  cadaver. 

The  histological  researches  of  Campbell,1  Brodmann 2  and  others  provide 
no  uniform  and  conclusive  data  respecting  the  function  of  the  parietal 
lobule  except  this  important  fact  that  it  is  later  in  development  than  the 
visuo-sensory  zone.  It  has  been  established  that  the  visuo-psychic  area 
extends  forwards,  merging  into  that  part  of  the  cortex  which  is  regarded 
as  the  inferior  parietal  lobule.  The  area  of  this  lobule  is  limited  above,  in 
front,  and  a  little  behind  by  the  inter-parietal  sulcus  and  comprises  the 
supra-marginal  convolution  and  the  anterior  portion  of  the  angular  gyrus 
(Figs.  1  and  4) .  Posteriorly  it  is  limited  by  an  imaginary  line  drawn  vertically 
from  the  occipi  to -parietal  fissure,  but  for  the  purposes  of  this  work  it  is 
unnecessary  to  enter  into  details  regarding  the  posterior  boundary.  In- 
f eriorly  it  is  limited  in  its  front  and  middle  portions  by  the  fissure  of  Sylvius, 
in  its  hind  portion  by  an  imaginary  prolongation  of  this  fissure  in  a  horizontal 
direction  to  the  point  where  it  meets  the  vertical  line  above-mentioned. 
This  clinico-morphological  boundary,  as  already  observed,  does  not  coincide 

1  Campbell.     Histological  Studies  on  the  Localisation  of  Cerebral  Function.     1905. 

2  Brodmann.     "  Beitrage  zur  histologischen   Legalisation    des   Grosshirnrinde," 
etc.     Journ.  f.  Psych,  und  Neurol.     1906. 

C 


34  THE  MECHANISM  OF  THE  BKAIN 

with  that  which  is  drawn  on  the  basis  of  cytotectural  studies.     Clinical 
observations  have  furnished  data  of  a  much  more  conclusive  character. 

Lesions  of  the  supra-marginal  convolution  and  the  anterior  part  of  the 
angular  gyrus  (the  area  LPI  indicated  with  small  circles,  Figs.  1  and  4) 
give  rise  to  disturbances  that  must  be  regarded  as  belonging  to  the  visual 
function.  Permanent  auditory  or  tactile  disorders  were  never  observed 
by  the  author. 

Auditory  disturbances  are  only  apparent  at  the  outset  of  the  condition  and 
are  fleeting  in  character  ;  or  they  may  make  their  appearance  if  the  lesion 
invades  also  the  superior  temporal  convolution.  Disturbances  of  tactile 
sensibility  are  only  observed  when  the  lesion  extends  from  the  parietal  field  to  the 
post-central  convolution. 

The  area  we  are  dealing  with  is  not  distinctly  and  precisely  delimited, 
and  it  seems  clear  that  the  variations  in  the  symptomatology  are  to  be 
explained  by  its  indefinite  continuation  and  merging  into  other  areas,  which 
have  fairly  well- denned  functions. 

The  disturbances  of  tactile  and  auditory  sensibility  which  complicate 
the  clinical  picture  in  parietal  lesions  do  not  depend  upon  the  fact  that  the 
inferior  parietal  lobule  forms  a  part  of  the  posterior  associative  zone  but 
upon  the  extension  of  the  lesion  into  anatomical  fields  that  involve  the  function 
of  hearing  or  of  tactile  sensibility  or  of  both. 

Both  the  supra-marginal  convolution  and  the  anterior  portion  of  the 
angular  gyrus  form  a  part  of  Wernicke's  zone,  but  the  writer  is  convinced, 
from  the  material  he  has  been  able  to  examine,  that  it  is  necessary  from  the 
pathological  point  of  view  to  divide  Wernicke's  zone  into  two  areas,  the 
temporal  (Fig.  1,  ZU)  and  the  parietal  (Fig.  1,  LPI). 

If  the  lesion  involves  the  whole  temporo-parietal  region  of  language  one 
can  understand  that  in  this  case  the  syndrome  will  be  very  complex.  Un- 
doubtedly this  is  the  chief  reason  why  this  region  of  the  neopallium  was 
considered  as  one  area,  after  Wernicke  and  Kussmaul l  had  established  therein 
the  seat  of  sensory  aphasia.  One  must  take  into  account  this  other  fact 
that  a  lesion  of  the  temporal  part  alone  of  Wernicke's  zone  gives  rise  to  a 
very  complex  syndrome,  just  as  if  the  lesion  extended  also  to  the  parietal 
portion,  so  that  it  is  not  easy  to  distinguish  between  symptoms  depending 
on  lesions  localised  in  the  temporal  lobe  and  those  affecting  also  the  inferior 
parietal  lobule.  The  complex  character  of  the  symptoms  produced  by  a 
lesion  limited  to  the  temporal  lobe  goes  to  prove  that  the  function  of  the 
parietal  area  of  language  is  in  this  case  merely  interdicted  (inhibited)  by  the 
lesion  limited  to  the  temporal  portion  of  the  zone  in  question. 

So,  too,  in  the  case  of  foci  limited  to  the  parietal  portion  of  Wernicke's 
zone,  we  get,  during  the  initial  period,  a  complex  syndrome,  which  includes  loss 
of  the  function  of  the  posterior  part  of  the  superior  temporal  convolution, 
though  this  is  of  short  duration. 

It  is  only  by  systematic  observation  of  these  patients  over  a  considerable 

1  Kussmaul.  "  Disordini  della  favella."  Ziemsen.  Patole  Terap,  vol.  xi.^ 
parte  3. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  35 

period  of  time  that  we  can  follow  the  gradual  disappearance  of  some  syrnp* 
toms  whilst  others  remain  unaltered  so  as  to  constitute  a  syndrome  that  is 
fairly  uniform  and  directly  attributable  to  the  lesion  of  the  parietal  area 
with  which  we  are  dealing. 

The  thing  that  stands  out  clearly  is  the  fact  that  small  cortical  or  sub- 
cortical  foci  in  the  superior  temporal  convolution  give  rise  to  symptomatic 
complexes  which  embrace  the  function  of  all,  or  a  large  part  of,  the  zone  of 
language  and  become  simpler  as  time  goes  on,  always  leaving  out  of  account 
secondary  lesions.  The  explanation  lies  in  the  intimate  nature  of  the 
anatomical  and  physiological  relations  subsisting  between  the  various 
elements  that  go  to  make  up  language,  a  point  that  the  writer  has  insisted 
upon.  Monakow  applied  the  term  diaschisis  to  this  relationship. 

The  syndrome  produced  by  a  lesion  of  the  left  inferior  parietal  lobule — 
for  we  are  dealing  for  the  moment  only  with  the  left  side — consists  of  certain 
symptoms  belonging  to  the  attack  itself  and  of  others  that  only  become 
evident  after  the  disappearance  of  these.  The  attack  may  assume  either  a 
vertiginous  or  an  apoplectic  form.  It  may  come  on  whilst  the  patient  is 
in  the  full  enjoyment  of  health.  As  a  rule,  the  patients  do  not  fall  but  are 
conscious  of  a  violent  stunning.  In  some  instances,  the  onset  of  the  malady 
is  in  the  form  of  an  ordinary  apoplexy. 

The  paralysis  or  paresis  of  the  right  side  need  not  be  dwelt  upon.  If 
present,  it  soon  disappears,  though  in  some  cases  it  persists,  in  varying 
degree,  for  some  time.  In  a  good  number,  if  not  in  the  majority,  of  cases, 
hemiansesthesia  is  found.  Of  this  symptom  we  shall  treat  later  on. 

After  the  attack  of  vertigo,  the  majority  of  patients  remain  as  though 
interdicted,  they  are  dysorientated,  know  nothing  and  have  no  memory. 
If  they  were  talking  at  the  time,  conversation  is  suddenly  interrupted  and 
they  do  not  understand  the  words  addressed  to  them.  If  they  attempt  to 
speak  they  utter  only  mutilated,  strange,  distorted  words  without  connection. 
They  have  no  clear  insight  into  their  condition.  Some  smile  and  continue 
to  speak  in  unintelligible  words  and  show  no  great  self-concern.  Others, 
again,  have  a  confused  notion  of  what  has  happened  to  them.  If  addressed 
by  those  around  them  as  if  nothing  had  occurred  they  reply  in  whispering 
incomprehensible  language.  I  remember  a  lawyer  giving  me  to  understand, 
many  weeks  after  his  attack,  the  great  surprise  he  felt  in  being  no  longer 
able  to  read  or  to  understand  anything  that  day  when  the  attack  came  on 
whilst  at  work  at  his  desk.  Immediately  after  the  onset,  all  patients  present 
symptoms  of  complete  or  incomplete  word-deafness,  and  paraphasia,  but 
none  shows  any  great  amount  of  self -concern  or  of  grief  such  as  is  generally 
exhibited  by  patients  who  lose  the  power  of  one  side  after  an  apoplectic 
attack  without  loss,  or  with  only  a  transient  clouding,  of  consciousness. 

At  the  outset,  the  somatic  complex  embraces  a  number  of  symptoms 
that  are  not  immediately  dependent  upon  the  part  destroyed  but  are  due  to 
functional  paralysis  of  areas  immediately  surrounding  the  parietal  lobule 
or  even  situated  at  some  distance  away.  In  the  motor  field,  e.g.,  we  have 
heniiparesis  of  the  right  side,  though  not  in  all  cases.  This  hemiparesis  is 


36  THE  MECHANISM  OF  THE  BRAIN 

fleeting  in  character  and  presents  no  special  feature  apart  from  the  lesser 
degree  of  the  paralysis  and  the  slighter  accentuation  of  the  tendinous  re- 
flexes of  the  paralysed  side,  as  compared  with  the  exaggeration  of  the  reflexes 
that  we  find  in  heniiplegia  due  to  direct  involvement  of  the  rolandic  system. 
Babinski's  sign  is  absent  and  the  author  has  never  observed  paralysis  or 
paresis  of  the  ocular  muscles. 

In  the  sensory  field,  tactile  and  muscular  hemiansesthesias  have  been 
frequent,  the  latter  being  the  more  marked.  Heat- sensibility  is  fairly  well 
preserved.  Astereognosis  is  very  frequent.  In  the  majority  of  cases  the 
hemiansesthesia  has  been  persistent. 

In  none  of  the  author's  patients  was  there  any  disturbance  of  taste  or 
of  smell. 

Homonymous  bilateral  hemianopsia  was  present  in  almost  every  case, 
in  quite  classic  form,  for  in  one  only  was  the  line  of  separation  of  the  blind 
field  of  vision  found  outside  the  point  of  fixation  and  in  one  only  was  it 
wanting. 

Signs  of  dysorientation  are  hardly  ever  absent  at  the  beginning.  By 
degrees  they  disappear.  Only  one  of  the  author's  patients  had  complete 
loss  of  memory  for  places  and  was  quite  unable  to  make  his  way  about  when 
outside,  so  that  he  was  obliged  to  have  someone  with  him  or  else  he  had  to 
ask  passers-by  the  way  to  his  home.1 

At  first  we  have  all  the  signs  of  complete  sensory  aphasia — word- 
deafness  (inability  to  understand  language  spoken  by  others),  loss  of  the 
capacity  to  give  grammatical  and  logical  expression  to  ideas,  mental  con- 
fusion, paraphasia,  amnesia  of  names  and  places,  alexia  and  agraphia. 

In  the  course  of  a  few  weeks  or  months  the  patient  by  degrees  begins  to 
re-establish  normal  relations  with  his  surroundings.  He  still  has  great 
difficulty,  however,  in  understanding  what  is  said  to  him,  but  if  the  phrases 
are  repeated  in  a  loud  voice  he  finally  succeeds  in  grasping  their  meaning. 
As  time  goes  on  the  patient  improves  definitely,  the  word- deaf  ness  diminishes 
and  he  gradually  regains  his  power  of  comprehension.  He  formulates  his 
thoughts  better  and  expresses  correct  phrases.  The  paraphasia  disappears, 
and  even  if  the  patient  still  distorts  some  words  he  is  able  to  correct  himself. 
The  most  persistent  symptom  is  alexia  (word-blindness)  and  with  this  there 
is  associated  a  certain  amount  of  verbal  amnesia,  a  torpid  state  of  intelli- 
gence, a  certain  degree  of  incoherence  and  not  infrequently  apraxia,  which 
may  last  for  some  time. 

If  the  patient  should  happen  to  be  a  highly  educated  person,  the  picture 
he  presents  from  the  beginning  is  much  more  serious  than  in  the  case  of  an 
illiterate  or  poorly  educated  individual.  The  loss  at  once  appears  enormous. 
The  man  of  ready  speech,  clear  and  correct  in  his  diction,  becomes  mute, 
stupid  and  void.  He  looks  with  questioning  eye  at  bystanders,  and  utters 
strange  phrases  consisting  of  mutilated  and  distorted  words.  He  fails  to 
understand  the  words  addressed  to  him  or  replies  with  dysphrasic  remnants 

1 L.  Bianchi.  "  Contribute  clinico  ed  anatomo-patologico  alia  dottrina 
della  cecita  verbale  (afasia  ottica)."  Ann.  di  Nev>  1891. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  37 

of  language.  Wherever  he  is,  he  loses  his  bearings.  Often  he  smiles  in  a 
stupid  fashion  and  remains  irresolute,  so  that  it  is  necessary  to  lead  him  away 
like  a  lost  infant. 

The  symptoms  are  incomplete  word-deafness,  verbal  and  syllabic  alexia, 
inability  to  write  any  normal  word,  or  at  the  most  he  may  write  his  own  name 
or  some  few  words  that  are  often  deformed  or  written  in  separate  syllables  ; 
inability  to  write  from  dictation  or  to  copy  ;  total  or  partial  inability  to 
repeat  words  pronounced  by  others,  and  impoverished  intellect  without 
evidence  of  any  regularly  formulated  thought.  Eight  hemiopia  and  right 
hemiansesthesia  are  very  frequent,  in  this,  as  in  the  preceding,  group. 

These  patients  often  show  marked  mental  confusion.  As  a  rule,  in  the 
course  of  weeks  or  a  few  months,  when  the  lesion  is  circumscribed,  the  mental 
condition  becomes  more  satisfactory  and  the  personality  seems  partly 
re-established.  In  those  cases  where  there  has  been  paralysis  of  the  right 
side  at  the  beginning  of  the  attack,  this  disappears.  Hemiansesthesia, 
unlike  the  hemiparesis,  does  not  disappear  entirely,  though  it  may  be  much 
diminished. 

Word-deafness  also  passes  off,  sometimes  incompletely,  but  the  patienls 
understand  most  of  the  questions  addressed  to  them  provided  these  are  net 
too  complicate  nor  put  to  them  too  rapidly,  one  after  another. 

Along  with  the  word-deafness  the  paraphasia  disappears.  Sometimes, 
however,  the  patients  still  distort  a  few  words,  not  always  the  same,  but 
words  suggested  can  be  understood  and  repeated  correctly.  Within  certain 
limits,  the  power  of  writing  to  dictation  is  regained.  The  other  symptoms 
remain  and  there  is  great  intellectual  impoverishment. 

In  the  illiterate,  the  syndrome  is  quite  insignificant. 

The  following  cases  fell  under  the  author's  personal  observation  and  they 
are  summarised  here  because  they  are  in  many  respects  demonstrative  and 
conclusive  : — 

Case.  1. — E.  G.  Aged  28.  Married.  Butcher.  Illiterate.  Drank  wine  to 
excess.  Mother  died  of  apoplexy.  Admitted  to  the  clinique,  29th  December  1909. 

About  a  year  and  a  half  before,  whilst  at  work,  he  had  an  attack  of  dizziness, 
followed  by  loss  of  consciousness.  When  he  came  to  himself,  two  hours  afterwards, 
he  was  unable  to  speak  and  had  paralysis  of  the  limbs  of  the  right  side. 

A  few  days  after  the  attack  he  regained  voluntary  movement  of  the  right  lower 
limb,  and  shortly  afterwards  of  the  upper  limb.  He  was  able  to  return  to  his  work 
as  a  butcher. 

Objective  examination  elicited  the  following: — Diminution  of  tactile  sensibility 
over  all  the  right  half  of  the  body,  slight  contacts  not  being  noticed  and  stronger 
contacts  only  confusedly,  and  badly  localised.  This  finding  was  confirmed  by  the 
use  of  the  aesthesiometer.  Heat  and  pressure  sensibilities  were  almost  normal. 
Muscular  sensibility  and  the  sense  of  position  of  the  limbs  on  the  right  side  were 
markedly  altered.  There  was  no  ataxia  but  with  his  eyes  bandaged  the  patient 
often  could  not  find  his  own  hand. 

The  stereognostic  sense  was  abolished,  to  the  extent  that  the  patient  could  not 
recognise  any  common  object  put  into  his  hand. 

Bilateral  homonymous  hemianopsia  on  the  right  side.  All  other  special  sensi- 
bilities normal. 


38  THE  MECHANISM  OF  THE  BRAIN 

Visceral,  genital  and  kinaesthetic  sensibilities  were  normal,  as  was  also  that  of 
space  and  the  relative  sense  of  orientation. 

Cutaneous  and  mucous  reflexes  weak  or  absent  on  the  right  side  and  lively  on 
the  left. 

Patellar  and  tendo-achillis  reflexes  somewhat  exaggerated  on  the  right  side. 
No  Babinski  reaction. 

No  paralysis  of  the  right  lower  limbs.  The  patient  walked  well.  There  was 
no  paresis  of  the  face  but,  when  the  patient  laughed,  facial  movements  appeared 
more  limited  on  the  right  side.  Paralysis  of  the  right  upper  limb  was  present, 
with  atrophy  of  the  muscles,  especially  of  the  triceps,  the  muscles  of  the  fore-arm 
and  of  the  thenar  eminence.  Electrical  tests  showed  diminution  of  faradic  and 
galvanic  excitability  in  these  muscles.  After  the  cerebral  attack,  a  polyneuritis 
extraneous  to  the  cerebral  disorder  was  superadded. 

No  disturbance  of  speech  and  no  alteration  of  intelligence.  For  all  purposes 
of  life,  this  patient  had  preserved  and  was  able  to  make  use  of  the  capital  of  thought 
and  of  language  that  he  had  acquired. 

Neither  in  the  clinique  from  the  time  he  .was  admitted,  nor  in  his  own  home, 
according  to  the  statement  of  his  wife,  an  intelligent  woman,  did  he  manifest  any 
mental  disorder  or  disturbance  of  speech,  for  he  had  regained  the  power  of  speech 
very  soon  after  the  attack. 

Apart  from  the  paralysis  of  the  upper  limb,  which  followed  upon  a  gastro- 
intestinal febrile  disorder,  (which  evidently  caused  a  polyneuritis  in  the  upper  arm 
in  an  individual  predisposed  thereto  by  alcoholism)  the  syndrome  presented  by 
this  patient,  much  more  extensive  immediately  after  the  attack,  became  reduced 
to  disturbances  of  sensibility  on  the  right  side,  especially  astereognosis  and  bilateral 
right  homonymous  hemianopsia.  The  increase  of  the  tendon-reflexes  on  the  right 
side  was  a  remnant  of  the  hemiplegia  from  which  he  had  suffered,  a  remnant  which 
is  very  common  after  a  destructive  focus  located  at  some  distance  from  the  motor 
area  and  the  corona  radiata. 

This  focus,  given  the  presence  of  hemiamesthesia  and  hemianopsia,  must  have 
been  situated  in  the  inferior  parietal  lobule,  must  have  extended  towards  the  ascend- 
ing parietal  convolution  and  reached  in  depth  to  the  optic  radiations  of  Gratiolet 
(thalamo-calcarine  fibres). 

This  view  of  the  localisation  is  strengthened  and  confirmed  by  other  cases  now 
to  be  recorded,  some  of  them  follo\ved  by  autopsy. 

Case  2. — L.  L.  Aged  55.  Professor  of  Literature  in  the  Lyceum.  Was  admitted 
to  the  clinique,  6th  November  1901.  Family  history  negative.  The  personal 
history  did  not  exclude  the  possibility  of  syphilis  as  a  youth.  On  22nd  October, 
while  conducting  his  class,  he  was  seized  with  vertigo  and  was  unable  to  continue 
speaking.  According  to  the  statement  of  the  person  accompanying  him,  he  was 
conducted  home  by  one  of  his  scholars,  in  an  almost  unconscious  condition.  There 
it  was  found  that,  along  with  serious  disturbance  of  speech,  there  was  paresis  of 
the  limbs  of  the  right  side.  This  paresis  disappeared  in  the  course  of  a  few  days. 
The  confusion  and  disturbance  of  speech  persisted  and  was  so  marked  on  the  days 
on  which  he  was  subjected  to  examination  that  it  was  impossible  to  decide  with 
certainty  whether  or  not  there  existed  any  disturbance  of  sensibility  on  the  right  side. 

Later  on,  one  could  say  that  tactile  sensibility  was  normal  but  even  after  some 
weeks  it  was  still  impossible  to  make  any  definite  pronouncement  as  to  the  state 
of  the  stereognostic  sensibility,  owing  to  the  serious  disturbance  of  language  and 
intelligence.  Hearing  was  normal  on  both  sides  ;  not  so,  sight,  for  as  soon  as  it 
was  possible  to  examine  him  with  the  perimeter  a  bilateral  homonymous  hemi- 
anopsia with  marked  restriction  of  the  visual  field  was  detected.  The  motor 
paralysis  had  disappeared,  so  that  there  was  no  indication  of  the  loss  of  power  so 
noticeable  on  the  22nd  October. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  39 

The  patient  was  a  man  of  culture,  knew  several  foreign  languages,  a  lover  of 
Dante,  and  could  repeat  from  memory  a  great  part  of  the  Divina  Commedia,  but 
now  remembered  nothing  of  these. 

He  could  not  repeat  a  single  verse  of  the  Divina  Commedia,  nor  could  he  give  a 
quotation  from  any  of  the  numerous  authors  with  whom  he  had  been  familiar. 
Not  a  word  could  he  say  of  the  languages  he  had  learned.  When  taken  into  the 
lecture-room  there  was  a  murmur  of  surprise  amongst  the  students,  some  of  whom 
recognised  in  him  their  old  Master  of  Literature.  To  them  it  was  a  cause  of  great 
surprise  that,  when  asked  to  repeat  something  from  Dante,  he  could  no  longer 
remember  anything  of  what  he  had  taught.  He  gave  us,  in  a  way,  to  understand 
how  great  was  the  misfortune  that  had  befallen  him  and  how  he  lamented  the  loss 
of  his  intellectual  capital.  The  amnesia,  however,  embraced  something  more  than 
matters  of  culture  alone.  The  associative  process  was  no  longer  so  well  ordered, 
so  that  he  made  mistakes  and  fell  into  dysphrasias  and  dyslogias.  If,  e.g.,  he  was 
asked  :  "  How  old  are  you  ?  "  he  replied  :"  22  ...  23  ...  26  ...  30  ...  10  ...  I 
could  begin  .  .  .  200."  Perceiving  he  had  said  something  foolish  he  then  com- 
menced to  count  from  1  upwards,  and  stopped  at  55,  which  was  the  figure  nearest 
to  his  age.  He  did  not  show  any  word-deafness  for  he  understood  all  the  questions 
put  to  him  and  that  without  much  delay  in  time.  When  in  the  course  of  my 
lecture  I  was  talking  of  him  and  of  the  signs  and  symptoms  he  manifested,  he 
frequently  caught  the  significance  of  what  I  was  saying  and  smilingly  nodded  if  it 
truly  corresponded  to  what  he  felt  and  appreciated.  He  understood  single  questions 
and  phrases  but  was  unable  to  follow  a  long  discourse.  Although  a  highly  cultured 
man,  he  remained  there  during  the  lecture  like  one  in  a  dream,  with  a  smile  playing 
around  his  lips.  When  it  was  over,  and  I  asked  him  if  he  knew  anything  of  what 
I  had  been  saying,  he  replied,  or,  rather,  implied,  with  a  slight  shrug  of  the  shoulders 
and  a  questioning  face,  that  he  had  not  understood.  Here  it  was  a  case  not  so 
much  of  true  word-deafness  as  of  interruption  of  the  paths  of  intellect  or  a  break- 
down of  one  of  the  essential  mechanisms  of  comprehension. 

Word-blindness  was  complete.  He  recognised  neither  words  nor  syllables. 
These,  to  him,  had  become  so  many  hieroglyphics  with  hidden  meaning. 

Word -blindness  without  word-deafness  persisted  for  some  years,  then  slightly 
improved  and  became  less  complete.  Alexia  passed  into  paralexia.  From  time 
to  time  the  patient  returned  to  the  clinique  for  examination  and  it  was  only  after 
a  long  period  and  many  hours  of  daily  exercise  that  reading  became  less  arduous 
work  ;  but  ho  forgot  immediately  what  he  read  as  well  as  what  he  heard.  As  for 
his  writing  it  was  greatly  altered  and  furnished  a  tangible  proof  of  the  mental 
decadence  of  this  poor  man. 

In  1905  he  had  improved  considerably  so  as  to  be  able  to  read  and  copy.  Regular 
and  methodical  examination  of  this'patient  proved  that,  as  he  regained  the  function 
of  spoken  language,  he  also  became  able  to  write  spontaneously  and  intelligibly. 
It  might  with  reason  be  held  that  the  partial  restoration  of  the  function  of  reading 
was  the  result  of  the  vicarious  development  of  the  homonymous  region  of  the  right 
side  or  of  the  portion  of  the  parietal  lobe  that  had  been  spared  by  the  lesion. 

During  all  the  time  this  patient  remained  under  observation  it  was  definitely 
ascertained  that  he  was  always  affectionate  towards  his  wife,  preoccupied  with 
his  family,  and  had  not  committed  any  strange,  incoherent  or  dangerous  actions, 
if  we  leave  out  of  account  the  first  stage  of  his  illness,  during  which  he  was 
dysorientated. 

In  this  case,  as  in  the  preceding,  two  features  stand  out  clearly  in  addition  to 
the  parietal  syndrome  :  (1)  well-preserved  affectivity  ;  (2)  consciousness  of  the  loss 
of  intellectual  capital  and  of  a  difference  between  the  present  state  and  that  which 
existed  prior  to  the  attack.  The  patient's  consciousness  of  his  past  intellectual 
personality  and  the  well-preserved  affectivity  are  characteristic,  one  might  say, 
of  this  variety  of  aphasic  dementia. 


40  THE  MECHANISM  OF  THE  BRAIN 

Case  3. — On  4th  May  1903,  C.  M.,  a  priest,  was  sent  to  the  Psychiatric  Clinique. 
In  January  of  the  same  year  he  had  had  an  attack  of  apoplexy  followed  by  a  right 
hemiplegia  which  disappeared  in  two  months.  It  appears  that,  following  upon 
the  cerebral  attack,  delusions  of  persecution  (not  uncommon  in  aphasics  in  the 
first  stage)  arose,  with  the  result  that  he  went  to  the  Police  Station  to  make  a 
charge  against  his  landlord.  There  it  was  not  difficult  for  the  officials  to  recognise 
that  he  was  profoundly  disordered  in  intellect,  and  they  had  him  sent  to  the  asylum. 
In  the  reception-room  he  had  the  appearance  of  one  stunned.  He  paid  no  heed 
to  his  new  surroundings,  passed  rapidly  from  an  angry  to  a  composed  state  of 
mind  and  did  his  best  to  make  us  understand  that  he  had  been  robbed  by  his  land- 
lord for  no  reason.  His  talk  was  confused,  paraphasic  and  paraphrasic. 

The  examination  revealed  tactile,  algesic,  thermal,  muscular  and  stereognostic 
hemianaesthesia  of  the  right  side  ;  bilateral  right  homonymous  hemianopsia  and 
slight  hypocophosis,  more  marked  on  the  right  side. 

Facial  movements  normal  on  both  sides.  No  disturbance  of  movements  of  the 
eyes,  tongue  or  limbs.  Muscular  force  was  diminished,  but  equal  on  both  sides, 
the  dynamometer  indicating  15  kilos  with  each  hand  and  22  kilos  with  both 
hands. 

Plantar  reflexes  absent  on  the  right,  lively  on  the  left  side.  Cremasteric  and 
abdominal  reflexes  absent  on  both  sides.  Patellar  reflex  stronger  on  the  right. 
Tendo-achillis  reflex  absent  on  both  sides.  No  Babinski  sign.  No  ankle-clonus. 
Gait  and  general  behaviour  quite  normal,  taking  into  account  the  advanced  age 
of  the  pitient. 

The  state  of  intelligence  can  be  summed  up  as  follows  : — Patient  generally  ex- 
hibited a  happy  frame  of  mind,  was  garrulous  and  liked  to  talk  with  all  near  him. 
He  comprehended  perfectly  well  the  nature  and  uses  of  the  various  articles  around 
him.  He  recognised  all  the  persons  who  attended  to  him,  showing  great  regard 
for  the  doctors  and  especially  the  chief  of  the  clinique.  He  understood  the  questions 
put  to  him,  provided  they  were  spoken  in  a  loud  voice,  in  short,  detached  phrases. 
Sometimes,  however,  he  did  not  understand  the  question  but  remained  in  an 
attitude  of  interrogation  so  that  the  question  had  to  be  repeated. 

He  showed  that  he  possessed  a  certain  experience  of  life,  but  in  speaking  did 
not  succeed  in  expressing  his  thoughts  fully.  His  talk  ended  by  being  rather 
dysphrasic.  Closer  examination  led  us  to  the  conviction  that  he  had  suffered  a 
real  loss  of  words  corresponding  to  the  things  he  wished  to  n"me  and  had  before 
him  in  his  mind,  whilst  his  pronunciation  of  many  words  was  so  transformed  and 
deformed  that  often  he  sought  to  make  himself  understood  by  means  of  circum- 
locutions and  gestures  and  hence  he  became  rather  incoherent. 

The  most  marked  deficit  consisted  especially  in  amnesia  of  proper  names  and 
names  of  objects,  even  the  very  commonest.  This  defect  was  rendered  very  evident 
when  he  was  asked  to  name  various  objects  handed  to  him  one  after  another. 
When  told  the  name  of  an  object,  he  sometimes  was  able  to  keep  in  mind  for  a  short 
time  a  sort  of  phonetic  image  of  .one  of  the  more  accentuated  syllables  of  the  word, 
and  with  this  he  would  compose  a  name  which  bore  some  slight  resemblance  to 
the  proper  word,  but,  taken  as  a  whole,  was  quite  a  new  and  meaningless  pro- 
duction. Thus,  he  would  say  laps  for  lapsis,  amello  for  anetto,  calamita  for  calamaio, 
rita  for  riga,  inghiorno  for  inchiostro,  callina  for  cartolina,  etc.  On  other  occasions, 
when  he  was  unable  to  pronounce  the  name  of  an  object,  he  tried  to  make  himself 
understood  by  indicating  its  use  or  by  mentioning  one  or  other  of  its  main  features. 
For  example,  on  showing  him  a  pen-holder,  he  said :  "  What  you  put  a  pen  near. 
I  have  a  lot  at  home."  On  showing  him  an  ink-bottle,  he  said  :  "  Where  you  put 
the  imp  or  ging."  On  handing  him  a  watch,  he  said  :  "  I  have  one  too,  of  gold. 
What  time  is  it  ?  "  etc. 

On  showing  him  various  objects  mixed  together  on  a  table  and  inviting  him 
to  take  up  one  after  another  by  merely  mentioning  the  names,  he  did  so  with 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  41 

promptitude  and  made  no  mistakes  and  knew  the  use  of  each  object  perfectly  well. 
(Normal  visual  perceptive  processes.)  If,  however,  he  was  asked  to  tell  the  name 
of  an  object,  he  failed.  As  sight  alone  was  not  sufficient  to  reawaken  the  verbal 
image  of  any  of  these  objects,  he  often  made  with  his  hand  the  movements  one 
generally  makes  when  using  a  particular  object,  and  in  this  way,  especially  after 
the  long  exercises  he  was  made  to  undergo  in  the  clinique,  he  sometimes  succeeded 
in  pronouncing  the  names,  key.  ring,  pen,  etc. 

It  is  important  to  note  that  the  patient  succeeded  more  rapidly  in  pronouncing 
the  name  of  an  object  that  he  took  in  his  left  hand,  with  eyes  closed — i.e.  when  he 
made  use  only  of  the  tactile  and  muscular  images — than  he  did  with  the  eyes  open, 
in  which  case  visual  images  were  associated  with  the  tactile. 

Reading  was  almost  entirely  forgotten  (word-blindness).  It  was  only  after 
the  patient  had  been  a  considerable  time  in  the  clinique  that  he  succeeded  in 


Fig.  9 

recognising  letters  and  syllables,  and  then  a  few  words,  but  in  reading  aloud  he 
substantially  altered  the  words  (paralexia)  and  he  never  quite  understood  the 
significance  of  any  writing  placed  before  him. 

Spontaneous  writing  was  limited  to  his  own  name,  and  numbers  up  to  ten. 
He  could  not  write  a  single  phrase  from  dictation  nor  could  he  even  copy,  in  a 
recognisable  manner,  the  two  words  "  provincial  asylum." 

He  remained  in  this  state  till  17th  June  1905.  He  was  composed,  correct  in 
his  behaviour,  respectful  and  sociable,  especially  with  the  doctors.  Death  occurred, 
19th  June  1905,  after  an  apoplectiform  attack. 

At  the  autopsy  a  single  large  focus  of  softening  was  found,  along  with  a  falling 
in  of  the  cortex,  in  the  region  of  the  left  inferior  parietal  lobule  (Fig.  9). 

The  focus  was  limited  in  front  by  the  anterior  branch  of  the  interparietal  sulcus. 
On  opening  up  the  sulcus  it  was  seen  that  the  lesion  extended  obliquely  downwards 
and  forwards,  reaching  the  grey  substance  of  the  posterior  aspect  (in  the  sulcus) 
of  the  ascending  parietal  convolution.  The  lesion  was  afterwards  found  to  extend 
in  depth  to  the  corona  radiata  and  the  middle  and  inferior  part  of  that  convolution. 
Above,  it  was  limited  by  the  interparietal  sulcus  following  the  curve  of  the  sulcus 
but  remaining  a  few  millimetres  below  it ;  behind,  it  reached  a  line  drawn  vertically 
in  the  direction  of  the  prolongation  of  the  occipito-parietal  fissure.  Below,  it 


42 


THE  MECHANISM  OF  THE  BRAIN 


invaded  the  posterior  end  of  the  superior  temporal  convolution  and  extended 
backwards  on  to  the  angular  gyrus. 

A  vertical  section  through  the  posterior  part  of  the  ascending  parietal  con- 
volution shows  clearly  the  lesion  of  the  corona  radiata  of  this  region  (Fig.  10). 

Another  section  through  the  centre  of  the  focus  parallel  with  the  first  shows 
quite  distinctly  that  it  reaches  in  depth  to  the  ventricular  ependyma,  interrupting 
the  course  of  the  optic  or  thalamo-cortical  fibres  and  even  those  of  the  tapetum 
(Fig.  11). 

Serial  sections  through  the  site  of  the  lesion  show  that  the  posterior  surface 
of  the  ascending  parietal  convolution  is  involved  in  the  area  of  softening.  At  this 
same  level  one  can  also  observe  the  lesion  of  the  superior  temporal  convolution. 


Fig.  10 


Fig  11. 


It  is  seen  to  be  limited  to  the  upper  portion  of  this  convolution,  the  remainder  of 
the  convolution  remaining  sound  (Fig.  12). 

The  lesion  becomes  gradually  more  restricted  as  it  extends  backwards,  as  shown 
by  a  series  of  sections  made  in  the  neighbourhood  of  the  anterior  liinits  of  the  visuo- 
psychic  area. 

The  rest  of  the  hemisphere  is  normal. 

To  sum  up,  the  focus  in  this  case  is  very  extensive,  for  it  involves  all  the  inferior 
parietal  lobule  within  the  limits  above  mentioned  and  also  extends  forwards  to 
the  radiations  of  the  tactile  area,  below  to  a  small  part  of  the  superior  temporal 
convolution,  and  in  depth  as  far  as  the  tapeium. 

This  finding  fully  explains  symptoms  observed  during  life.  The  disturbances 
of  tactile  sensibility,  of  hearing,  speech  and  sight,  should  not  be  described  as 
dependent  upon  a  lesion  occupying  an  associative  area  in  the  sense  of  Flechsig 
(interruption  of  the  paths  for  intercortical  association).  Rather  should  we  say 
that  the  tactile  disturbances  depend  directly  upon  a  lesion  of  the  ascending  parietal 
convolution  and  its  corona  radiata  (pay  Fig.  12)  (the  cortical  organ  of  tactile  sensi- 
bility) ;  the  visual  disorders  were  due  to  interruption  of  the  optic  radiations  of 
Gratiolet  (destroyed  along  the  line  marked  E),  the  word-deafness  that  existed  at 
the  beginning  and  the  verbal  amnesia  were  evidently  due  to  a  partial  lesion  of  the 
superior  temporal  convolution  (Fig.  11  and  ts  of  Fig  12). 

The  disappearance  of  the  word-deafness  and  the  general  restoration  of  the  psychic 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  43 

personality  can  be  attributed  to  the  fact  that  the  superior  temporal  convolution 
was  in  great  part  spared  and  able,  in  the  course  of  time,  to  resume  its  functions 
(after  disappearance  of  the  symptoms  of  diaschisis),  whilst  the  word-amnesia 
remained,  as  usual,  to  testify  to  the  functional  weakness  of  the  organ  where  word- 
images  are  conserved  and  reproduced — viz.  the  superior  temporal  convolution. 

Case  4. — Zi.  P.,  aged  67  years,  a  man  of  fairly  good  education.  Admitted  to  the 
clinique,  January  1906. 

In  August  1905  he  had  had  an  apoplectic  attack  of  which  the  only  sign  that 
remained  after  a  few  weeks  was  a  slight  dragging  of  the  right  leg,  as  he  walked. 


Fig.  12 

pa.  Ascending  parietal  (damaged). — E.  Ependyma,  with  a  portion  of 
the  fibres  of  the  tapetum. — ts.  Superior  temporal  convolution, 
damaged  in  part 

Movements  of  the  right  arm  appeared  normal  but  the  dynamometer-reading  on 
the  right  side  was  12  kg.  and  on  the  left  17i  kg. 

The  deep  reflexes  were  exaggerated  on  the  right  side,  rather  weak  on  the  left. 
There  was  also  anaesthesia  on  the  right  side,  not  only  of  tactile  sensibility  but  also 
of  pressure  and  heat  and  at  the  same  time  diminution  of  the  muscular  sense  and 
abolition  of  the  stereognostic  sense.  With  eyes  closed  the  patient  recognised  none 
of  the  common  objects  put  into  his  right  hand  although  the  movements  of  his 
fingers  were  normal.  All  the  special  senses  were  normal.  No  bilateral  homony- 
mous  hemianopsia.  At  the  examination  immediately  after  admission  there  was 
noted  a  marked  mental  weakness.  He  had  no  idea  where  he  was,  did  nob  recognise 
it  to  be  an  asylum,  and  generally  appeared  to  be  very  confused. 


44  THE  MECHANISM  OF  THE  BRAIN 

He  had  lost  the  capacity  to  read.  He  saw  the  written  words  quite  well,  but 
although  he  was  able  to  recognise  the  majority  of  the  letters  composing  each  word, 
he  could  on  longer  recognise  words  as  a  whole. 

He  heard  and  understood  perfectly  well  words  and  phrases  addressed  to  him. 
There  was  never  any  paraphasia.  He  could  write  only  his  name  and  surname, 
nothing  else.  He  was  unable  to  write  from  dictation.  With  great  difficulty  ho 
succeeded  in  copying  short  words,  reproducing  them  better  from  the  printed  form, 
as  from  a  design.  He  was  quite  incapable  of  transcribing  printed  letters  into 
handwriting. 

He  had  forgotten  a  remarkable  number  of  nouns  so  that  his  speech  became  slow 
and  he  was  incapable  sometimes  of  expressing  his  thought  owing  to  this  defect  in 
vocabulary.  He  was  dysphrasic  and  void.  He  showed  no  initiative  in  conversa- 
tion with  the  doctors.  He  had  difficulty  in  giving  expression  to  a  single  thought 


Fig.  13 

F.  Destructive  focus 

or  desire  and  for  months  he  remained  mute  yet  quite  conscious  of  his  insufficiency 
and  of  his  inability  to  formulate  and  give  expression  to  thoughts. 

This  patient,  when  re-examined  several  times  during  the  years  1906-1907, 
presented  always  the  same  syndrome.  Towards  the  end  of  1907,  his  mental  con- 
dition became  worse  and  he  showed  symptoms  of  word-deafness  and  all  the  features 
of  auditory  aphasic  dementia. 

Dementia  and  word-deafness  by  degrees  became  very  profound.  Death 
occurred  2nd  February  1909. 

The  results  of  the  post-mortem  examination  were  as  follow:  — 

On  external  examination  the  hemispheres  appeared  normal.  No  focus  was 
visible  on  the  cortex ;  only  an  area  of  depression  about  3-  cm.  in  diameter,  in  the 
upper  and  anterior  part  of  the  inferior  parietal  lobule,  near  the  interparietal  sulcus. 
The  posterior  part  of  the  left  hemisphere  seemed  smaller  than  the  right,  especially 
the  temporal  lobe. 

There  are  here  reproduced  three  transverse-vertical  sections  of  the  brain. 
The  first  section  was  made  through  the  ascending  parietal  convolution.  In  its 
upper  limits  it  cuts  also  the  ascending  frontal  and,  in  its  lower  portion,  the  anterior 
part  of  the  inferior  parietal  lobule,  corresponding  to  Nos.  86  and  89  of  the 
transverse-vertical  sections  described  by  Dejerine.  The  left  hemisphere  is  here 
seen  to  be  smaller  than  the  right.  There  is  shown  a  focus  of  softening  apparently 
limited  in  front  by  the  interparietal  sulcus  but  in  fact  extending  forwards  and  down- 
wards to  the  radiations  of  the  ascending  parietal  convolution.  In  depth  it  extends 
to  a  point  3  or  4  mm.  above  the  ependyma  of  the  lateral  ventricle.  At  this  point 


EVOLUTION  OF  THE  NERVOUS  SYSTEM 


45 


a  good  part  of  the  upper  portion  of  the  supra-marginal  convolution  is  also  involved 
(Lob.  par.  inf.,  Fig.  4)  and  there  is  evident  injury  to  the  tactile  radiations  of  the  ascend- 
ing parietal  convolution.  There  is  no  direct  injury  to  the  temporal  lobe  (Fig.  13). 

The   next  section,  made   further   behind,  shows  the  focus  to  be  much  more 
circumscribed.     It  involves  the  grey  substance   and  the  radiations  of  the  supra- 


Fig.  14 

marginal  gyrus  in  its  anterior  superior  aspect,  bordering  on  the  interparietal  sulcus, 
and  dips  down  as  a  tunnel  into  the  white  substance  of  the  ascending  parietal  con- 
volution, at  this  point  considerably  removed  from  the  temporal  lobe,  which  never- 
theless seems  somewhat  shrunken.  The  lesion  reaches  in  depth  to  the  centrum 


Fig.  15 

ovale,  to  witnin  a  few  millimetres  of  the  ependyma,  but  remains  much  above  and 
in  front  of  the  path  of  the  optic  radiations  of  Gratiolet. 

The  third  section  (Fig.  15),  made  a  few  millimetres  behind  the  preceding,  still 
shows  the  focus  quite  distinctly,  but  here  it  is  much  smaller.  It  involves  a  small 
tract  of  the  radiations  of  the  ascendin  parietal  convolution  above  and  in  front 
and  the  anterior-superior  part  of  the  supra -marginal  gyrus  behind  and  below.  It 
dips  down  deeply  into  the  centrum  ovale  but  remains  above  and  in  front  of  the 
path  of  the  radiations  of  Gratiolet. 


46  THE  MECHANISM  OF  THE  BKAIN 

Apart  from  the  atrophy  of  the  left  hemisphere,  and  particularly  of  the  temporal 
lobe,  atrophy  that  was  certainly  secondary  and  late,  on  which,  too,  depended  the 
late  word-deafness  with  symptoms  of  dementia,  the  great  interest  of  this  case  lies 
in  the  pure  form  of  alexia  along  with  a  particular  form  of  dementia,  the  conspicuous 
symptoms  of  verbal  amnesia,  and  the  absence  of  hemianopsia  from  the  onset  of 
the  attack. 

The  absence  of  word-deafness  was  due  to  the  fact  that  the  focus  was  at  some 
considerable  distance  from  the  superior  temporal  convolution  and  did  not  even 
destroy  the  whole  of  the  supra-marginal. 

Hemianopsia  was  absent  because  the  focus  did  not  extend  behind  and  deep 
enough  to  affect  the  paths  of  the  thalamo-occipital  radiations.  The  syndrome — 
alexia  and  amnesia — can  only  be  related  to  the  partial  subcortical  destruction  of 
the  supra-marginal  convolution,  whilst  the  complicating  hemiansesthesia,  with  loss 
of  the  stereognostic  sense,  must  be  attributed  to  injury  to  the  radiations  of  the 
ascending  parietal  convolution. 

It  is  thus  proven  that  alexia  is  a  symptom  associated  with  lesions  of  the 
parietal  zone  independently  of  any  lesion  of  the  thalamo-occipital  visual 
paths. 

If  lesions  in  the  posterior  part  of  this  parietal  zone  produce  alexia  and 
hemianopsia  (when  they  are  deep,  as  in  Cases  2  and  3)  it  is  because  the 
bundle  of  Gratiolet  is  involved.  Classical  hemiansesthesia  and  hemiagnosis 
are  only  produced  when  the  lesion  extends  to  the  corona  radiata  of  the 
ascending  parietal  convolution  or,  at  least,  to  the  anterior  branch  of  the 
interparietal  sulcus,  because  the  area  of  tactile  hemiansesthesia  and  agnosis 
is  situated  in  the  cortex  of  the  antero-superior  branch  of  the  interparietal 
sulcus,  and  especially  in  the  precincts  of  the  ascending  parietal  convolution 
and  its  corona  radiata.  Again,  intellectual  disturbances  in  educated  men 
are  to  be  put  down  directly  to  the  alexia,  and  hence  to  the  lesion  of  the 
inferior  parietal  lobule,  inasmuch  as  this  is  the  visual  organ  of  language, 
in  educated  men  an  organ  of  high  value. 

* 
*  * 

From  the  point  of  view  of  intelligence  the  patients  above-mentioned 
can  be  divided  into  two  groups,  one  being  formed  of  those  individuals  who 
had  acquired  a  fair  degree  of  culture  and  the  other  consisting  of  illiterate 
individuals  or  those  who  had  learned  to  read  and  write,  but  had  hardly 
cultivated  those  faculties  to  any  extent.  The  clinical  histories  of  some  of 
the  patients  whom  the  author  has  been  able  to  keep  under  observation  for 
a  long  time,  following  them  even  to  the  post-mortem  table,  support  this 
distinction.  We  are  here  dealing  with  different  levels  of  mental  development 
according  to  the  degree  of  culture,  and  the  syndrome  varies  in  accordance 
with  the  richness  or  otherwise  of  the  mental  capital  acquired  by  means  of 
reading,  and  with  the  extent  and  depth  of  the  focus. 

With  regard  to  the  amnesia  and  the  conspicuous  intellectual  impoverish- 
ment that  are  displayed  as  a  result  of  more  or  less  extensive  lesions  of  the 
inferior  parietal  lobule  it  may  be  asked  :  "  Are  these  due  to  the  fact  that 
this  area  forms  a  part  of  the  language-zone  or  are  we  to  account  for  them 
independently  of  the  function  of  language  by  saying  that  the  area  in  question 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  47 

forms  a  part  of  the  posterior  associative  zone  of  Flechsig  ?  "  The  cases 
above  mentioned  do  not  furnish  arguments  in  favour  of  Flechsig 's  doctrine. 

If  the  parietal  area  were  the  zone  of  passage,  or  the  meeting-place  of 
paths  for  cortical  association  of  visual,  auditory  and^tactile  images,  a  sort 
of  laboratory  where  images  of  various  kinds  are  combined  (associated)  so 
as  to  furnish  intellectual  products  of  a  higher  order,  then  the  symptoms 
dependent  upon  lesions  of  this  area  would  be  more  uniform  in  all  the  patients 
afflicted.  It  is  to  be  noted,  however,  that  in  some  men,  as  in  the  priest  in 
Case  3,  even  very  extensive  lesions  give  rise  to  symptoms  that  are  relatively 
insignificant  so  far  as  the  intellect  is  concerned  whilst  the  functional  deficit 
(alexia)  is  always  of  a  visual  order,  yet,  in  other  cases,  although  the  lesions 
are  comparatively  slight,  the  loss  is  enormous.  It  is  thus  evident  that  the 
loss  finds  its  explanation  not  in  the  fact  that  the  lesion  destroys  a  part 
of  the  brain  that  is  anatomically  and  physiologically  identical  in  all  men, 
but  in  the  fact  that  the  function  of  that  area,  essentially  visual,  is  not  equally 
developed  in  all  alike.  If,  in  the  case  of  the  priest,  C.  M.,  the  symptomatic 
complex  at  the  beginning  of  the  attack  and  a  considerable  time  after  was 
serious,  taking  into  account  the  nature  of  the  intellectual  disturbance 
(extensive  amnesia  and  confusion) ,  that  was  because  the  lesion  of  the  parietal 
lobule  extended  to  the  superior  temporal  convolution.  This  patient  was 
word-deaf  and  we  know  that  along  with  word- deaf  ness,  in  consequence  of 
lesions  of  the  superior  temporal  convolution,  we  have  symptoms  of  an 
imposing  nature  referable  to  the  intelligence  (mental  confusion  and,  not 
infrequently,  hallucinations  and  delusions) .  The  word-deafness,  indeed,  was 
not  the  effect  of  mere  solidarity  of  the  various  areas  of  language  but  was 
the  direct  result  of  the  lesion  of  the  auditory  area  of  speech. 

It  can  reasonably  be  held  that  the  exemption  of  the  greater  part  of  the 
auditory  zone  of  language  from  injury  (vide  Figs.  9,  11  and  12)  explains  why 
this  was  paralysed  and  interdicted  in  the  first  stage  but  was  able  gradually 
to  regain  its  function  whilst  at  the  same  time  the  personality  and  intellect 
became  recomposed,  inasmuch  as  many  images  and  memories  of  things 
were  able  to  come  into  the  field  of  consciousness  associated  with  their  respec- 
tive verbal  images.  The  personality  was  enabled  to  display  itself  again  in 
all  the  manifestations  of  mental  life  and  with  the  old  normal  characteristics, 
though  no  doubt  limited  in  potentiality  and  in  extent. 

Further,  although  it  is  true  that  our  priest  was  rather  ignorant  and  from 
the  time  of  his  youth  had  not  opened  a  book  nor  read  a  journal  except  the 
Office  which  he  had  repeated  for  years  in  an  automatic  fashion,  and  a  popular 
dream  book  by  the  aid  of  which  he  sought  to  interpret  the  dream  that  should 
bring  him  fortune,  it  is  not  at  all  improbable  that  in  his  case  the  word- visual 
sphere  had  been  sufficiently  exercised  in  his  youth  in  the  course  of  the  studies 
necessarily  associated  with  his  ecclesiastic  career.  Had  he  never  opened 
another  book  after  he  first  took  Mass  nor  again  exercised  his  visual  area, 
but  had  centralised  the  dynamism  of  language,  and  hence  of  thought,  wholly 
or  to  a  great  extent  in  the  auditory  area  alone,  one  could  not  deny  that  his 
visual  area  was  yet  to  some  extent  more  active  than  that  of  an  uneducated 


48  THE  MECHANISM  OF  THE  BRAIN 

and  illiterate  person.  In  this,  I  believe,  is  to  be  found  the  reason  why  the 
dementia  in  his  case  was  marked  at  the  outset  and  why  it  gradually  dis- 
appeared as  the  auditory  area,  which  was  almost  completely  spared,  gradually 
resumed  its  linguistic  function. 

This  explanation  does  not  exclude  the  possibility  of  compensation  on 
the  part,  also,  of  the  right  hemisphere. 

In  the  patient  mentioned  in  Case  4  the  syndrome  was  almost  identical, 
but  at  no  time  was  there  ever  word- deaf  ness  or  paraphasia  because  the  lesion 
was  situated  at  some  considerable  distance  from  the  superior  temporal  con- 
volution, which  undoubtedly  exercises  a  strong  regulative  influence  over  the 
motor  centre  of  speech  (wherever  that  may  be).  The  alexia  was  absolute 
and  word-amnesia  very  marked,  although  the  focus  in  the  inferior  parietal 
area  was  much  smaller.  Here  the  explanation  lies  in  the  fact  that  this  man, 
though  an  artisan,  was  a  habitual  reader  and  spent  his  evenings  in  teaching 
children. 

If  we  accept  the  doctrine  of  Flechsig.  and  take  the  anatomical  fact  of  the 
existence  of  a  preponderating  number  of  associative  fibres  mingled  and 
interlaced  with  a  smaller  number  of  projection  fibres,  as  Dejerine  afterwards 
demonstrated,  as  a  proof  of  the  high,  intellectual  function  of  this  area  of  the 
cerebral  cortex,  we  should  still  have  to  explain  the  very  marked  difference 
that  occurs  in  the  case  of  educated  as  compared  with  illiterate  individuals  ; 
and  we  should  always  expect  to  find  the  same  symptomatology  following 
destructive  foci  in  that  region,  just  as  we  expect  in  the  case  of  lesions  of  the 
motor  or  the  occipital  area.  The  enormous  difference  between  the  effects 
of  the  large  focus  found  in  the  brain  of  the  ignorant  C.  M.  and  the  very 
serious  effects  suffered  by  the  well-read  patient  of  Case  2,  and  the  compara- 
tively minor  disturbances  in  Case  4,  must  point  to  a  functional  difference 
which  would  seem  to  be  the  result  of  long  exercise  and  of  the  differentiation 
of  the  area  in  question,  giving  rise  to  a  special  function  which  is  altogether 
absent  in  the  illiterate  individual  and  not  more  than  faintly  outlined  in 
those  who  have  merely  learned  to  read  and  write,  but  have  failed  to  acquire 
a  linguistic  and  intellectual  capital  by  a  regular  course  of  reading. 

So  far  as  sight  and  touch  are  concerned,  the  difference  in  the  sympto- 
matic complex  must  be  attributed  to  the  precise  site  and  extent  of  the  focus, 
a  fact  of  which  there  is  ample  available  proof. 

To  the  writer  these  observations  prove  that  the  images  of  the  graphic 
symbols  are  formed  in  the  evolutionary  area  of  the  visual  cortical  field  and 
are  reproduced  there  in  situ.  Destruction  of  this  area  renders  impossible 
the  perception,  recognition  (word-blindness)  and  reproduction  of  those 
symbols  because  the  whole  of  this  vast  associative  mechanism  becomes 
interdicted  and  this  applies  both  to  the  images  of  the  various  external  objects 
that  have  been  gradually  formed  in  the  different  perceptive  areas  and  to 
conceptions  compounded  of  these.  It  is  clear  that  this  area  becomes  an 
associative  field  by  a  specific  evolution  of  the  visual  function  without  on  that 
account  losing  any  of  its  characteristics  as  a  perceptive  area.  What  may 
seem  a  common  meeting-ground  and  an  area  of  interlocking,  using  the 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  49 

terminology  of  Luciani,  is  simply  one  field  made  up  of  functionally  differenti- 
ated areas  situated  close  to  one  another  so  that  a  destructive  focus  produces 
a  syndrome  that  is  more  or  less  complex,  dependent  not  only  on  the  evolu- 
tionary dignity  of  the  particular  area  or  areas  concerned  but  on  the  material 
injury  to  one  or  more  of  the  surrounding  areas  or  their  projection- bundles, 
according  to  the  site,  extent  and  depth  of  the  focus. 

In  the  case  of  individuals  who  have  read  a  great  deal,  one  can  reasonably 
suppose  that  the  visual  images  of  things — and  in  aphasics  these  persist  and 
are  perfectly  capable  of  being  recalled — reawaken  the  corresponding  graphic 
images  more  readily  than  the  phonetic  images  of  these  objects.  It  is  clear 
that  in  the  case  of  educated  and  cultured  men  the  area  of  the  graphic  images 
may  become  a  mechanism  of  great  importance  in  the  formation  and  move- 
ment of  thought,  and  consequently,  when  this  mechanism  is  destroyed, 
the  intellectual  capital  can  no  longer  be  reproduced  in  the  language  with 
which  it  is  essentially  bound  up,  language  which  is  the  one  thing  indis- 
pensable for  its  sensible  manifestation,  although  that  intellectual  capital 
may  yet  be  in  existence  like  -so  many  deposits  of  constructive  material. 
If  we  break  the  pendulum  of  a  clock  we  stop  the  movement  of  the  entire 
system  of  wheels,  yet  the  mechanism  of  the  clock  remains  sound  and  is 
capable  of  performing  its  work,  provided  a  new  pendulum  is  substituted. 
What  happens  in  the  case  of  lesions  of  the  language-zone  is  quite  analogous. 
Just  as  the  auditory  cortical  area,  during  the  very  long  period  that  has 
been  required  for  the  formation  of  language,  has  been  undergoing  a  gradual 
process  of  differentiation  so  as  to  give  rise  to  a  specialised  area  for  the  forma- 
tion and  conservation  of  the  phonetic  images  of  things  and  their  relations, 
so  too,  in  a  much  later  epoch  we  have  had  in  the  case  of  the  visual  zone — i.e. 
in  the  area  destined  for  the  formation  and  conservation  of  the  visual  images 
of  things — a  process  of  differentiation  giving  rise  to  a  special  area  where  are 
formed,  registered  and  conserved,  the  images  of  the  graphic  symbols  of  things 
and  their  relations.  In  other  words,  a  part  of  the  visual  area  becomes 
transformed  into  an  organ  which  gives  products  that  are  analogous  (because 
they  are  essentially  visual)  but  of  a  higher  order. 

Our  contention  that  the  area  of  formation  of  the  sensory  symbols  of 
thought  may  be  an  associative  centre  of  the  first  order  is  based  on  the  notion 
that  the  products  of  work  of  the  cerebral  cortex  must  in  turn  be  reflected 
towards  the  sensory  organ  of  speech  inasmuch  as  they  all  tend  to  find  their 
respective  verbal  symbol  and  to  become  fused  with  it.  It  is  through  the 
operation  of  this  centre  and  by  means  of  the  graphic  symbols  that  con- 
sciousness extends  and  comes  into  relationship  with  the  whole  of  humanity. 
It  is  an  indisputable  fact  that  destruction  of  the  language-zone  does  not 
merely  suppress  the  register  of  words  but  puts  out  of  gear  the  whole  functional 
mechanism  of  the  brain.  Hence  the  very  marked  disorder  and  enfeeblement 
of  mind  associated  with  word- deaf  ness  and  paraphasia,  conditions  which 
on  post-mortem  examination  we  find  to  be  related  to  a  destructive  focus  in 
the  left  superior  temporal  convolution.  From  this  point  of  view,  Flechsig's 
first  conception  would  appear  to  be  an  unnecessary  complication,  incapable 


50  THE  MECHANISM  OF  THE  BRAIN 

of  proof,  not  based  on  clinical  and  anatomical  findings  nor  yet  essential 
for  the  interpretation  of  the  mental  mechanism. 

Pierre  Marie  inclines  to  the  view  that  the  inability  of  the  word- deaf  to 
understand  spoken  language  is  a  consequence  of  their  dementia.  I  do  not 
see  how  this  can  be  proved,  nor  is  there  any  apparent  reason  for  the  inversion 
of  the  formula. 

The  view  that  the  patient  who  suffers  from  word- deaf  ness  is  demented 
because  the  lesion  which  produces  the  sensory  aphasic  syndrome  destroys 
a  centre  that  is  essential  for  the  formation  and  flow  of  thought  is  one  that 
is  readily  capable  of  proof.  The  analogy  of  the  broken  pendulum  comes  in 
here. 

Now,  the  reasoned  views  we  have  put  forward  with  regard  to  the  auditory 
area  of  language  are  equally  applicable  to  the  visual  area,  with  this  limita- 
tion, that  in  the  former  case  they  apply  to  men  in  general  and  in  the  latter 
only  to  some,  for  it  must  ever  be  borne  in  mind  that,  in  the  case  of  the 
illiterate,  the  visual  area  remains  undifTerentiated.  In  those  in  whom  it  has 
been  developed,  it  also  acts  as  a  meeting-place  for  many  mental  products, 
and  hence  is  an  associative  zone  of  inestimable  intellectual  value,  though 
not  in  the  sense  of  Flechsig. 


* 
*  * 


Let  us  now  turn  our  attention  to  the  temporal  lobe  which,  with  the 
occipital  lobe  and  the  inferior  parietal  lobule,  completes  the  great  temper o- 
parieto-occipital,  or  posterior  associative  zone  of  Flechsig.  We  will  pass 
in  rapid  review  the  really  reliable  observations  made  on  this  region,  few  in 
number  as  they  are,  and  seek  to  arrive  at  some  conclusion  as  to  its  function. 

It  is  needless  to  reproduce  the  old,  fantastic  ideas  concerning  the  function 
of  this  as  of  other  areas  of  the  brain.  To  give  one  example  only,  one  might 
instance  Burdach,  who  said  of  the  temporal  lobe  that  "  It  belongs  to  the 
motor  activity  of  the  mind."  Again,  "Its  relations  with  the  cingulum 
(organ  of  imagination),  with  the  optic  thalamus  (organ  of  general  sensibility 
and  of  will),  with  the  anterior  commissure  (organ  of  sensible  intuition  and 
of  the  corporal  will),"  with  the  occipital  lobe,  the  anterior  lobe  and  the  island 
of  Reil,  gave  rise  to  the  notion  that  its  function  was  eminently  psychic.1 

More  recently,  thanks  to  the  researches  of  Hitzig,  Ferrier,2  of  Luciani  and 
Tamburini,3  and  of  Munk,4  a  better  founded  idea  of  the  function  of  the  whole 
temporal  lobe  has  been  arrived  at. 

On  exciting  with  electricity  the  superior  temporal  convolution  in  the 
monkey  and  in  the  dog,  the  most  constant  response  is  movement  of  the  ear. 
With  a  stronger  current  there  is  produced,  in  addition,  widening  of  the 
palpebral  fissure,  movements  of  the  head  and  eyes  towards  the  opposite 
side  and  dilatation  of  the  opposite  pupil. 

1  Soury.     Systeme  nerveux  central.     Paris,  1899. 

2  Ferrier.     Loc.  cit. 

3  Luciani  and  Tamburini.     Rivista  Sperimentale  di  Freniatria.     1889. 

4  Munk.      Vber  die  Functionen  des  Grosshirnrinde.     1890. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  51 

The  experimental  destruction  of  this  area  led  Ferrier,  and  Luciani  and 
Tamburini,  to  conclude  that  it  was  the  cortical  centre  of  hearing,  because 
this  function  was  abolished  after  extensive  bilateral  destruction  of  the  area 
concerned. 

Meanwhile  the  syndrome  of  sensory  aphasia  (word- deaf  ness)  was  becom- 
ing gradually  denned  and  brought  into  relation  with  a  lesion  of  the  posterior 
part  of  the  superior  and  middle  temporal  convolutions  in  man.  The  litera- 
ture of  this  subject  has  grown  enormously  from  the  time  of  Wernicke, 
Kussmaul  and  Charcot,  up  to  the  present  day.  Experimental  and  clinical 
data  now  available  prove  clearly  that  the  temporal  lobe  is  the  organ  of 
hearing  and  comprises  the  organ  of  fundamental  hearing  in  its  acoustico- 
sensory  area  (the  transverse  temporal  convolution,  Fig.  5,  auditory  sphere), 
and  the  organ  for  the  audition  of  speech,  and  hence  for  the  formation  and 
conservation  of  verbal  and  musical1  acoustic  images,  in  the  surrounding 
acoustico -psychic  sphere,  the  boundaries  of  which  are  indefinite. 

I  give  here  several  unpublished  observations  that  are  useful  in  helping 
us  to  form  a  notion  of  the  physio -pathology  of  the  temporal  lobe.  The  scope 
of  this  volume  does  not  permit  a  full  review  of  all  that  is  to  be  found  in  the 
literature  of  the  subject. 

I  have  no  intention  of  dealing  with  destructive  foci  limited  to  the  language 
zone  (posterior  parts  of  the  superior  and  middle  temporal  convolutions, 
ZU,  Fig.  1  and  Tl,  Fig.  4).  The  symptomatology  of  this  area  coincides  with 
the  story  of  sensory  aphasia  (word- deaf  ness)  concerning  which  there  is  a  very 
rich  literature  in  all  languages.  Small  foci,  occurring  not  in  Wernicke's 
zone  (temporal  section)  but  in  a  more  or  less  distant  point  of  the  same 
temporal  lobe  may  reveal  themselves  in  the  symptomatic  complex  of  the 
so-called  amnesic  aphasia.  This,  however,  is  due  not  to  destruction  but 
rather  to  functional  paresis  of  the  area  of  aphasia  owing  to  a  lesion  in  its 
neighbourhood  (a  small  focus  or  commencing  tumour  2). 

Case  5. — A  man  of  about  forty  years  was  admitted,  to  the  asylum  in  a  state  of 
advanced  dementia.  Repeated  observations  revealed  the  existence  of  complete 
word-deafness  with  suppression  of  all  manifestations  of  thought  either  spontaneous 
or  induced.  The  patient  did  not  reply  to  a  single  question.  There  was  complete 
mental  arrest  so  far  as  one  could  judge  from  the  entire  absence  of  any  form  of 
language.  There  was  no  sign  of  paralysis.  There  was  blindness  with  choked  disc 
and  secondary  neuro-retinitis.  He  remained  in  this  state  for  about  fifteen  days, 
when  pulmonary  complications  set  in,  followed  by  death.  On  post-mortem  examina- 
tion, the  whole  loft  temporal  lobe  from  the  sphenoidal  extremity  to  the  occipital 
pole  was  found  transformed  into  a  hard  mass  which  had  no  longer  the  appearance 
of  cerebral  tissue.  On  section  the  new  growth  was  seen  to  be  of  a  sarcomatous 
nature. 

Case  6. — A  woman  of  seventy  years  was  admitted  into  the  asylum  suffering 
from  severe  dementia.  There  was  no  physical  sign  of  functional  disturbance  in 
the  field  of  sensibility,  neither  was  there  disturbance  of  movement  in  any  part  of 
the  body  nor  alteration  of  the  reflexes.  There  was  well-marked  deafness  on  the 

1  Ingenieros.     Le  langage  musical.     Paris,  1907. 

2  Bianchi.     "  L'afasia  amnesica."     Ann.  di  Nev.     1914. 


52  THE  MECHANISM  OF  THE  BRAIN 

right  side.  It  was  impossible  to  learn  whether  or  not  she  had  suffered  from  an 
ordinary  apoplectic  attack.  The  mental  examination  revealed  very  severe  word- 
deafness.  She  did  not  understand  a  single  word  addressed  to  her.  Her  attention 
could  be  attracted  by  calling  her  in  a  loud  voice  or  tapping  her  with  the  hand,  but 
she  very  rapidly  relapsed  into  unintelligible  talk.  She  chattered  constantly  but 
few  of  her  words  had  any  resemblance  to  those  found  in  the  vocabulary  of  the 
Italian  language.  They  were  almost  entirely  fragments  of  words  or  words  quite 
altered  in  structure  (paraphasia).  Never  a  phrase  or  proposition  did  we  hear 
formulated  by  her  on  grammatical  lines.  She  called  things  by  the  most  extrava- 
gant names,  composed  of  a  confused  conglomeration  of  syllables.  There  was  no 
such  thing  as  grammatical  inflexion  ;  at  most,  her  talk  consisted  of  a  few  distorted 
words  and  these  were  pronounced  ad  infinitum.  To  sum  up,  we  had  here  word- 
deafness,  amnesic  aphasia,  paraphasia,  akataphasia,  dysphrasia  and  alogia.  She 


Fig.  16 

showed  indifference  towards  everyone  and  everything  and  was  sometimes  filthy 
in  her  habits  (aphasic  dementia). 

It  so  happened  that  there  was  another  woman  of  the  same  age  in  the  clinique 
at  the  same  time.  She  too  was  illiterate,  and  displayed  similar  symptoms,  though 
less  severe.  This  patient  died  and  on  post-mortem  examination  we  found  a  large 
destructive  focus  involving  the  posterior  half  of  the  superior  and  middle  temporal 
convolutions  and  a  good  part  of  the  inferior  parietal  lobule.  I  was  therefore 
induced  to  make  a  similar  diagnosis  in  the  present  case — i.e.  a  large  destructive 
focus  in  the  zone  of  Wernicke.  The  patient  died  from  pulmonary  complications. 

Post-mortem  examination  revealed  the  existence  of  very  advanced  primary 
sclerotic  atrophy  of  the  whole  left  temporal  lobe,  which  had  become  reduced  to 
little  more  than  half  the  size  of  the  right  temporal  lobe.  Histological  examination 
revealed  the  presence  of  a  magnificent  growth  of  neuroglia,  with  dense  network 
and  bundles  of  fibres,  atrophy  and  disappearance  of  the  nerve-cells.1 

Case  1. — A  woman  of  forty-eight.  Her  illness  commenced  with  attacks  of 
vertigo  and  confusion.  Then  came  an  attack  of  classical  epilepsy,  which  com- 

1  Franceschi.  "  Gliosi  perivascolare,  in  un  caso  di  demenza  afasica.  Annali 
di  Nevrologia.  1908 


EVOLUTION  OF  THE  NERVOUS  SYSTEM 


53 


menced  in  the  right  side.  After  the  lapse  of  two  months  there  was  another  epileptic 
attack,  and  this  was  followed  by  headache,  localised  in  the  left  side  of  the  head, 
and  by  a  fleeting  disturbance  of  speech.  Later  on  there  was  paresis  of  the  right 


Fig.  1' 


IS 


side,  which  afterwards  developed  into  hemiplegia  whilst,  at  the  same  time,  a  state 
of  dementia  developed  and  became  very  severe  in  the  course  of  a  few  weeks.  She 
showed  great  difficulty  in  comprehending  words  and  phrases  spoken  by  others. 
There  was  amnesia  not  only  of  words  but  of  things,  persons  and  events.  Visual 
disturbances  supervened,  and  later  on  complete  blindness,  with  choked  disc.  The 


54 


THE  MECHANISM  OF  THE  BRAIN 


dementia  made  such  rapid  progress  that,  with  the  physical  blindness  and  the  word- 
deafness,  the  patient  lost  all  relations  with  her  surroundings.  Difficulty  in  deglu- 
tition set  in.  There  was  conjugate  deviation  of  the  head  and  eyes.  Speech  was 
entirely  absent.  The  patient  did  not  understand  a  single  word  addressed  to  her. 
Sometimes  she  would  turn  her  head  slowly  towards  the  side  of  the  speaker  if  he 
addressed  her  repeatedly  in  a  loud  voice,  or  she  would  open  her  eyes,  or  groan,  or 
give  a  cry. 

On    post-mortem    examination,    the   left   superior    temporal    convolution    was 
found  to  be  about  half  the  breadth  of  that  of  the  right  side.     Measured  in  the  same 


tm 


Fig.  19  (cross-section) 

a.  Claustrum.— o.  Operculum.—  ce.  Outermost  capsule.—  i.  Island  of  lleil.— bi.  Limits 
of  focus  in  neighbourhood  of  Island  of  Reil. — b.  Focus. — ts.  Superior  temporal 
convolution. — tm.  Middle  temporal  convolution 

vertical  plane,  the  height  of  the  left  temporal  lobe  was  45  mm.,  and  of  the  right 
50  mm.  (Figs.  16  and  17).  After  immersion  of  the  brain  in  fixing  fluid,  parallel 
antero-posterior  sections  were  made  and  a  large  cancerous  mass  was  found  occupy- 
ing the  position  of  the  corpus  callosum,  no  trace  of  which  remained.  The  mass 
had  grown  particularly  towards  the  left,  in  a  direction  outwards  and  backwards, 
destroying  first  the  sensory  and  motor  paths  then  all  the  basal  ganglia  (corpus 
striatum  and  optic  thalamus),  and  infiltrating  behind  into  the  corona  radiata  of 
the  upper  two  temporal  convolutions  (Fig.  18).  The  last-mentioned  finding  ex- 
plained the  atrophy  of  the  superior  temporal  convolution,  the  word-deafness  and 
the  severity  of  the  dementia  as  compared  with  what  has  been  found  in  other  cases 
of  tumour  of  the  corpus  callosum.1 

1  Bianchi.     Atti  delV  Accademia  medico-chirurgica  di  Napoli.     1915. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM 


55 


Case  8.1— C.  D.  was  admitted  to  the  asylum  on  1st  March  1894,  and  died  there 
fourteen  days  later.  From  the  time  of  admission  till  his  death  he  could  not  express 
a  single  thought  in  proper  words. 

His  language  was  reduced  to  a  veritable  jumble  of  words,  these  being  quite 
wasted,  broken  and  distorted.  His  words  were  composed  in  strange  and  varying 
fashion,  new  syllables  and  various  vocal  sounds  being  introduced  and  letters  added 
here  and  there  without  order.  For  example,  he  would  say  "  onno  managgio  "  for 
"  voglio  mangiare,"  etc.  He  seemed  to  be  in  despair  because  unable  to  express  his 
own  thoughts,  and  to  be  conscious  of  the  mistakes  he  made.  He  tried  to  correct 


/        ?       , 


ti 


Tim 


Fig.  20 

fl.  Pronto-insular  angle. — cc.  External  capsule.— nm.  Corona  radiata  of  the  two  superior 
temporal  convolutions,  the  tibres  of  which  must  pass  by  ti  and  f,  through  the 
outermost  capsule  and  the  external  capsule,  cc 

himself,  only  to  fall  into  worse  error.  He  retained,  however,  a  certain  power  of 
mimicry  corresponding  to  his  thoughts  and  emotions,  and  so  one  was  able  to  some 
extent  to  decipher  his  jargon  and  have  it  confirmed  by  him.  He  would  try  to 
say  :  "  I  am  very  distressed  because  I  cannot  speak,"  and  many  were  his  exclama- 
tions of  despair  at  his  futile  attempts. 

He  understood  the  brief  questions  that  were  put  to  him,  and  when  told  once  or 
twice  to  make  a  certain  movement,  did  so.  Sometimes  he  made  use  of  normal 
words,  but  they  were  out  of  place  and  quite  incoherent.  Once  when  asked  :  "  What 
is  wrong  with  you  ?  "  he  replied  :  "  First  of  first  I  have  done."  To  :  "  How  old 
are  you  ?  "  he  replied :  "  What  you  want  !  Yes  !  Four  days  !  "  Another  man 
who  lay  opposite  him  used  to  address  him  in  a  disdainful  manner.  Our  patient, 
listening,  would  frown  at  him,  then  give  vent  to  an  oath  very  common  among 
Neapolitans,  his  voice  and  pronunciation  in  this  case  being  decided  and  correct 
(as  often  happens  with  aphasics). 

1  Bianohi.  "Trattato  delle  malattie  del  cervello."  Patologia,  by  Cantani  and 
Maragliano.  Vol.  ii.,  parte  2. 


56 


THE  MECHANISM  OF  THE  BRAIN 


He  recognised  letters,  syllables  and  words,  but  jumbled  them  in  reading  almost 
as  he  did  in  speaking. 

He  could  write  spontaneously  but  rather  slowly,  in  a  large  and  childish  hand, 
but  the  words  were  distorted.  He  could  copy  very  well. 

At  the  post-mortem  examination  an  old  focus  of  white  softening  was  found  in 
the  left  hemisphere.  The  whole  of  the  anterior  part  of  the  temporo-sphenoidal 
lobe  resembled  a  sack  filled  with  a  milky,  whitish,  .pultaceous  material  which 
escaped  on  making  a  fronto-peduncular  section  of  the  brain,  this  section  going 
through  the  anterior  extremity  of  the  temporo-sphenoidal  lobe. 

The  next  section  was  made  through  the  line  of  junction  of  the  frontal  con- 
volutions with  the  ascending  frontal,  and  is  represented  by  Fig.  19.  The  space  b, 
from  which  the  liquid  material  has  escaped,  is  seen  to  occupy  the  position  of  the 
white  substance  of  the  anterior  extremities  of  the  first,  second  and  part  of  the 
third  temporal  convolutions.  It  extends  considerably  inwards  and  also  upwards 


Fig.   21 — Left  hemisphere 

l.T.   Superior    temporal    convolution.— 2.T.     Middle.— 3.T.     Inferior    temporal    convolution  — 
y.  Destructive  focus 

to  a  point  close  to  the  white  substance  of  the  insula  bi,  so  that  the  long  stretch  of 
fibres  running  from  the  temporal  lobe  to  the  insula  is  destroyed. 

On  making  another  vertical  section,  one  centimetre  behind  the  former  but  still 
in  front  of  the  supposed  anterior  limit  of  the  auditory  area  'of  speech  in  the  superior 
temporal  convolution  (Fig.  20),  the  position  of  the  focus  of  softening  (b)  is  seen  to 
be  such  that  it  interrupts  the  nervous  paths  leading  from  the  superior  and  middle 
temporal  convolutions  to  the  frontal  operculum.  The  focus,  in  fact,  runs  in  a 
longitudinal  or  antero-posterior  direction  for  half  the  length  of  the  first  and  second 
temporal  convolutions  and  extends  inwards  into  the  white  substance  of  the  tem- 
poral lobe,  so  that  all  communication  between  the  latter  and  the  operculum  of  the 
ascending  frontal  and  the  inferior  frontal  convolutions  must  have  been  destroyed. 

The  fibres  nm  can  only  run  through  a  certain  tract  in  the  two  temporal  con- 
volutions, gradually  leaving  which  they  curve  round  the  temporo-insular  sulcus  ti, 
passing  into  the  grey  substance  of  the  insula  or  into  the  outermost  capsule  (ce, 
Fig.  19),  some  perhaps  into  the  external  capsule  (ce,  Fig.  20).  They  then  bend 
round  the  fr  on  to -insular  sulcus  fi  to  reach  the  foot  of  the  inferior  frontal  con- 
volution, represented  in  the  figure  by  the  anterior  part  of  the  Rolandic  operculum, 
the  foot  of  the  frontal  convolution  (being  in  front  of  the  section. 

The  posterior  limit  of  the  focus  of  softening  remains  in  front  of  the  posterior 
third  of  the  temporal  convolutions.  This  localisation  affords  an  explanation  of  the 
clinical  picture.  The  patient  heard  and  understood  because  the  auditory  centre 
was  sufficiently  sound  and  in  relation  with  the  peripheral  organs  and  the  sub- 
cortical  stations  of  hearing  and  also  with  a  good  part  of  the  rest  of  the  cerebral  cortex, 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  57 

so  that  intelligence  was  in  great  part  preserved.  He  could  articulate  syllables 
and  words  because  the  kinsesthetic  centre  of  spoken  speech  was  untouched.  He 
could  copy  because  the  visuo-cheiro-kinaesthetic  (Bastian)  and  audito-cheiro- 
kina^sthetic  paths,  as  well  as  the  corresponding  centres,  were  undamaged.  Classical 
parapbasia  and  paragraphia  were  present  because  the  motor  centres  of  spoken  and 
of  written  language  respectively  were  withdrawn  from  the  control  of  the  acoustico- 
sensory  centres.  The  lesion  disturbed  the  whole  linguistic  mechanism  by  reason 
of  the  interruption  of  the  associative  paths  between  the  sensory  centre  and  the 
motor  centre  of  spoken  language  (in  bi,  Fig.  19  and  ti,  Fig.  20),  and  also  by  sup- 
pression of  the  grammatical  inflexions.  Indeed,  the  most  important  feature  was 
the  dysphrasia  and  the  alogia,  closely  related  as  these  were  with  the  absolute  in- 
capacity for  the  inflexion  of  verbs  and  the  intuition  and  expression  of  the  tenses. 

Case  9.1 — P.  G.,  born  1863,  subject  to  convulsions  from  infancy,  associated  with 
a  nervous  temperament  and  a  distinctly  epileptic  character. 


Fig  22. — Vertical  section  through  the  centre  of  the  destructive  focus 

S.  Fissure  of  Sylvius. — l.T.  Superior  temporal. — 2.  Middle  temporal. — 
3.  Inferior  temporal  convolution  (almost  entirely  destroyed). — 
A.  Lesion  of  grey  substance  of  superior  temporal  convolution 

He  had  learned  no  trade  but,  being  obliged  to  earn  his  own  living,  found  em- 
ployment as  a  domestic.  He  was  fortunate  in  finding  mistresses  who  put  up  with 
him  and  he  was  able  to  get  along  for  a  time  because  his  convulsions  were  not  frequent, 
and  he  passed  as  quiet  and  respectable  though  really  captious  and  turbulent.  In 
the  course  of  time,  his  convulsions  became  more  frequent  and  were  followed  by 
mental  disturbances  that  became  more  prolonged  and  more  severe.  His  psychic 
life,  abnormal  to  begin  with,  now  underwent  a  process  of  constant  deterioration, 
and  at  last  he  had  to  be  sent  for  care  and  treatment  to  the  asylum. 

In  the  later  stages  of  his  trouble  his  convulsions  became  exceptionally  severe, 
and  were  followed  by  agitation  and  delirium  lasting  for  several  days.  When  the 
post-convulsive  confusion  passed  off  he  talked  constantly.  Sometimes,  indeed, 
he  was  very  talkative  immediately  after  the  convulsion.  The  rapid  deterioration 
of  his  already  weak  intellect  and  the  meekness  that  took  the  place  of  his  former 
impulsiveness  were  remarkable  features  of  the  last  stages.  The  clinical  picture 
was  the  very  common  one  of  the  epileptic  character  with  recurrent  accessions  of 

1  L.  Bianchi.  <(Su  di  un  caso  di  lesione  destruttiva  del  lobo  temporo- 
sfenoidale  sinistro."  La  Psichiatria,  etc.  1888. 


58  THE  MECHANISM  OF  THE  BRAIN 

epileptic  psychosis,  ending  in  post-epileptic  dementia.  Death  followed  upon  a 
convulsion  at  a  time  when  he  was  a  physical  wreck. 

A  post-mortem  examination  was  made.  In  addition  to  pulmonary  and  cardiac 
lesions  and  senile  changes,  an  old  apoplectic  cyst  was  found  in  the  left  hemisphere, 
exactly  in  the  middle  part  of  the  temporo-sphenoidal  lobe  little  more  than  4  cm. 
in  length  and  3  cm.  in  breadth  (Fig.  21).  The  second  temporal  convolution  was 
completely  destroyed,  along  with  the  neighbouring  part  of  the  grey  substance  of 
the  superior  convolution  in  the  superior  temporal  sulcus.  The  greater  portion  of 
the  inferior  temporal  convolution  was  also  destroyed,  only  a  narrow  strip  of  grey 
substance  remaining  at  its  lower  edge. 

Fig  22.  represents  a  vertical  section  through  the  cyst  in  the  temporal  lobe 
and  shows  clearly  the  extent  and  depth  of  the  lesion. 

No  doubt  a  lesion  such  as  that  met  with  in  the  case  above  described  may 
well  have  been  expected  to  have  given  rise  during  life  to  particular  symptoms 
of  dementia,  because  it  did  damage  to  a  conspicuous  portion  of  the  posterior 
zone  of  Flechsig  both  on  the  surface  and  in  its  depth.  Yet  the  fact  remains 
that  classic  aphasic  dementia  did  not  exist,  very  probably  because  the  seat 
of  the  focus  was  in  front  of  and  below  Wernicke's  zone  and  wholly  in  the 
posterior  associative  zone  of  Flechsig.  Not  even  verbal  amnesia  was  present. 

In  the  light  of  Flechsig' s  doctrine  we  ought  to  have  found  complex 
disturbances  of  intelligence  in  this  as  in  the  previous  case.  On  the  contrary, 
the  dementia  exhibited  by  this  patient  was  late  in  appearance  and  was  not 
attributable  to  that  old  cyst.  It  had  all  the  features  of  classic  dementia 
described  by  psychiatrists  as  post- epileptic  dementia,  common  enough  in 
all  asylums — i.e.  an  enfeeblement  of  mind  in  toto,  superimposed  upon  the 
purely  epileptic  character  such  as  the  patient  had  shown  from  his  early  youth. 
The  patient  was  left-handed,  so  that  the  absence  of  any  disturbance  of  speech 
could  be  attributed  to  the  fact  that  he  spoke  with  his  right  hemisphere. 
But  this  very  fact  goes  to  prove  that  the  particular  intellectual  disturbances 
that  accompany  lesions  of  the  temporal  lobe  are  in  relation  with  the  physio - 
pathological  mechanism  of  language,  a  function  which  in  this  case  was 
discharged  by  the  right  hemisphere.  In  other  words,  they  depend  upon 
destruction  of  the  archives  of  the  word-images  (and  hence  of  the  vocabulary) 
formed  and  conserved  in  loco  and  in  anatomico-physiological  relation  with 
the  whole  sensory  cortex,  and  upon  damage  to  the  grammatical  mechanism 
which  would  appear,  from  the  facts  at  our  disposal,  to  be  located  in  that  region. 

In  some  cases  of  tumour  of  the  temporal  lobe  reported  by  Kennedy 1  the 
most  important  symptoms  met  with  were  some  alterations  of  language, 
frequent  amongst  these  being  inability  to  recall  the  names  of  objects.  In 
other  cases  the  aphasic  syndrome  was  more  or  less  conspicuous. 

The  paraphasia  observed  in  some  of  these  patients  is  often  due  to  the 
defective  representation  of  substantive  names  which  are  necessary  for  the 
formation  of  phrases  and  propositions. 

Paralogia,  like  dysphrasia,  depends  partly  upon  amnesia  of  nouns  and 
verbs,  which  causes  the  patients  to  lose  the  thread  of  their  discourse  and  to 

1  Kennedy.  "  The  Symptomatology  of  Temporo-Sphenoidal  Tumours.  Archives 
of  Internal  Medicine.  1911. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  59 

give  utterance  to  phrases  that  have  nothing  to  do  with  the  premises,  and 
partly  upon  the  lack  of  ability  to  give  words  their  proper  inflexion. 
Agrammatism  is  a  frequent  condition  in  those  who  suffer  from  word- deaf  ness 
but  it  also  is  due  to  deficient  grammatical  inflexion  of  verbs.  There  is  reason 
to  believe  that  this  grammatical  deficiency  has  a  considerable  influence  upon 
the  orientation  of  consciousness  in  time,  because,  after  all,  grammatical 
inflexions  correspond  to  a  mental  disposition  which  transports  the  actual 
moment  of  the  psychic  process  into  the  past  and  into  the  future. 

Intuitions  of  time,  the  duration  of  periods  of  time  and  rhythm,  are 
intimately  bound  up  with  hearing  and  with  auditory  perceptions.  Indeed 
this  function,  in  addition  to  constituting  a  part  of  the  mental  patrimony, 
furnishes  ontogenetic  experimental  data  in  the  evolution  of  the  personality  for 
abstract  intuitions  of  time,  for  the  orientation  of  the  person  in  time  and  for 
the  grammatical  inflexions  which  express  the  corresponding  psychic  situations. 

It  is  apparent  that  the  temporal  lobe  contributes  largely  to  the  formation 
and  development  of  thought,  but  its  contribution  is  very  different  from  that 
provided  respectively  by  the  occipital  lobe  and  the  inferior  parietal  lobule 
and  it  is  of  an  exclusively  acoustico-perceptive  character. 

The  great  variety  of  symptoms  and  the  differences  in  the  clinical  pictures 
met  with  as  the  result  of  destructive  lesions  of  the  inferior  parietal  lobule 
and  of  the  temporal  lobe  do  not  harmonise  with  the  notion  of  functional 
uniformity,  such  as  has  been  ascribed,  more  or  less,  to  the  great  posterior 
associative  zone.  We  are  probably  much  nearer  the  truth  if,  like  Bohn,  we 
say  that  many  regions  of  the  brain,  and  especially  those  that  surround  the 
bottom  of  the  fissure  of  Sylvius,  are  new  and  unexplored  regions,  full  of  possi- 
bilities for  the  future,  regions  which  one  day  will  be  the  centre  of  a  marvellous 
human  advancement.  That  Flechsig  attributes  a  single  function  to  this 
zone,  as  a  whole,  can  also  be  inferred  from  Hitzig's  communication  to  the 
Congress  at  Paris.1 

In  formulating  his  conclusions  regarding  the  great  'posterior  association- 
centre  Hitzig  wrote  as  follows  : — "  Flechsig  regards  it  as  the  organ  which 
forms  and  re-unites  the  representations  of  external  objects  and  the  phonetic 
images  of  words  and  their  combinations,  and  if  this  be  so,  it  would  therefore 
be  the  organ  of  positive  cognition  properly  so  called,  as  welt  as  the  organ  of 
imaginative  activity  of  representation,  the  organ  for  the  preparation  of 
speech  according  to  the  thought-content  and  the  organ  of  verbal  form — in 
short,  the  organ  of  the  most  essential  elements  of  what  in  ordinary  language 
is  specially  designated  as  thought."  2 

This,  however,  is  surely  a  remodelled  interpretation  of  Flechsig's  idea. 
It  agrees,  in  part,  with  the  view  the  author  put  forward  very  explicitly  in  a 
communication  to  the  Congress  at  Madrid,3  when,  in  dealing  with  dis- 
turbances of  intellect  following  upon  lesions  of  the  region  in  question,  he 

1  Hitzig.      "  Les    centres    de     projection    et    les     centres    d'association,"    etc. 
Nevraxe,  vol.  i. 

2  Hitzig.     LOG.  tit. 

3  Bianchi.     LOG.  cit. 


60  THE  MECHANISM  OF  THE  BRAIN 

maintained  that  these  were  purely  aphasic  disorders.  Yet  Flechsig  adds  that 
it  is  the  organ  of  positive  cognition — which,  on  the  contrary,  has  its  organs 
in  the  sensory  zones — and  of  the  imaginative  activity,  thus  reaffirming  the 
old  conception,  which  we  will  deal  with  in  the  following  chapters. 

Lesions  of  the  temporal  lobe  do  not  give  rise  to  disturbances  of  move- 
ment nor  do  they  cause  disorders  of  tactile  and  muscular  sensibility.  In  all 
those  cases  in  which  the  lesions  were  limited  to  the  temporal  lobe,  though -at 
the  same  time  fairly  extensive,  tactile  sensibility  was  found  to  be  normal. 
These  lesions  do  not  produce  visual  disturbances  unless  they  extend  in  depth 
to  the  optic  paths  of  Gratiolet.  The  visual  and  tactile  areas  always  furnish 
their  normal  products  (positive  cognition),  with  this  difference,  that  they 
cannot  combine  with  their  respective  words,  the  register  of  which  is  destroyed, 
a  fact  which  explains  the  special  behaviour  of  the  intelligence  in  aphasics. 

The  temporal  lobe  contributes  to  the  formation  and  manifestation  of 
intellect  not  only  by  means  of  the  simple  auditory  images,  which  represent 
one  of  the  modes  by  which  the  world  is  revealed  to  us,  but  especially  by  means 
of  language.  It  is  by  means  of  language  that  we  are  enabled  to  recompose 
in  our  minds  our  world  of  cognitions,  along  with  the  ever-growing  and 
manifold  network  of  our  social  relations,  which  offer  an  ever- increasing 
scope  for  the  exercise  and  development  of  intellect. 

When  we  speak  of  language  we  mean  language  with  all  its  inflexions, 
and  these  are  intellectual  in  character.  Undoubtedly  language  exercises 
an  enormous  influence  upon  the  structure  and  power  of  intellect. 


* 
*  * 


The  various  questions  we  have  thus  far  dealt  with  have  a  distinct  bearing 
upon  the  fundamental  problem  which  it  is  proposed  to  elucidate  in  this 
volume. 

One  cannot  arrive  at  a  clear  conception  of  the  function  of  the  frontal 
lobe  unless  one  knows  something  of  the  contribution  rendered  by  other 
definite  areas  of  the  brain  and  unless  one  is,  at  the  same  time,  conversant 
with  all  the  facts  that  hitherto  have  been  ascertained  regarding  the  complex 
and  intricate  function  of  the  cerebral  cortex.  Proceeding  along  these  lines 
one  may  hope  at  least  to  lay  the  foundation  of  a  more  promising  anatomical 
psychology,  more  promising  because  founded  on  facts,  for  in  the  past  it  has 
suffered  from  the  prevalence  of  conceptions  that  have  been  rather  one-sided. 


* 
*  * 


We  come  now  to  the  motor  area.  If  it  is  to  be  considered  as  a  projection- 
zone  one  can  readily  understand  that  it  must  receive  all  the  nerve-waves 
frorn  the  tactile  and  the  other  sensory  areas  so  as  to  render  possible  the 
relative  reactions  upon  the  external  world.  It  is  to  the  cortex  of  the  brain 
what  the  anterior  cornua  are  to  the  posterior  cornua  and  the  sensory  paths 
of  the  spinal  medulla.  In  each  case  centripetal  waves  arrive  at  the  motor 
centres  and  after  traversing  these  are  reflected  upon  the  muscular  apparatus. 
The  fibres  of  intercommunication  between  the  tactile  area  (ascending 


EVOLUTION  OF  THE  NEKVOUS  SYSTEM  61 

parietal)  and  the  motor  area  (ascending  frontal)  are  exceedingly  numerous. 
As  compared  with  the  sub -cortical  and  medullary  motor  centres  we  have 
here  a  difference  only  in  the  degree,  dignity  and  number  of  the  components. 
The  motor  area  reflects  upon  the  external  world  the  number  and  nature  of 
the  single  or  combined  psycho -sensory  products  which  excite  it. 

It  is  always  the  first  to  be  myelinised  and  it  is  marked  No.  1  in  Flechsig's 
scheme.  There  is  evidence  to  show  that  the  fibres  first  myelinised  are  not 
the  only  ones  which  arrive  at  the  motor  zone,  so  that  this  area  really  serves 
as  an  associative  area  of  considerable  value. 

At  the  front  of  the  motor  zone,  almost  forming  a  part  of  it,  there  is  an 
area  which  extends  towards  the  bases  of  the  frontal  convolutions  and  is 


Fig.  23 

m.  Motor  area 

regarded  by  some  authors  as  an  integral  part  of  the  motor  area.  De  Boyer 
and  Pitres  1  and,  generally  speaking,  Charcot's  school  regard  the  motor  zone 
as  extending  somewhat  in  front  of  the  ascending  frontal  convolution. 

Several  reliable  observations  go  to  prove  that  this  narrow  zone  of  extension 
and  evolution  of  the  motor  area,  and  in  particular  the  middle  portion  of  it, 
serves  as  the  field  of  extension  of  the  motor  area  of  the  upper  limb  for  the 
complex  movements  involved  in  particular  professions,  such  as  writing. 
The  histological  researches  of  Campbell,  Bolton,  Brodmann  and  Flechsig 
go  to  confirm  this  view.  Further  confirmation  has  been  afforded  by 
physiological  and  pathological  investigations  (Chapter  III.,  intermediate 
motor  zone).  Indeed,  it  would  seem  that  any  new  work,  if  intense  and 
prolonged,  leads  not  only  to  the  perfecting  of  the  primary  function  but  to 
a  further  extension  of  the  functioning  surface  of  the  cortex.  Doubts  have 
been  thrown  upon  the  existence  of  a  centre  for  writing,  especially  by  Dejerine 
and  Mirallie,2  but  it  is  probable  that  prolonged  practice,  such  as  is  involved 

1  De  Boyer    and    Pitres.     Etudes   topographiques   sur   les   lesions   corticales   des 
hemispheres  cerebraux.     1879. 

2  Dejerine  and  Mirallie.     De  I'aphasie  sensorielle.     1896. 


62  THE  MECHANISM  OF  THE  BRAIN 

in  the  automatism  of  writing  with  the  right  hand  or  the  automatism  of  the 
violinist  or  the  pianist,  must  bring  about  the  formation  of  a  centre  or  cortical 
area  adapted  for  a  particular  co-ordination  of  movements,  a  centre  which  is 
distinct  from  that  of  the  ordinary  movements  of  the  upper  limb,  movements 
involving,  e.g.,  prehension,  defensive  actions  and  the  grosser  occupations 
directed  towards  the  preservation  of  the  individual  and  towards  industrial 
production. 

No  doubt  one  can  write  with  the  left  hand,  or  with  a  pen  held  in  the 
mouth  or  with  the  foot,  or  fixed  even  on  the  trunk  of  the  body.  These  are 
facts  that  have  been  amply  demonstrated  by  the  results  of  re-education 
amongst  those  who  have  suffered  loss  of  limbs  during  the  great  war.  They 
prove,  at  most,  that  new  motor  co-ordinations  are  possible  in  all  muscular 
fields  as  the  result  of  exercise,  but  they  do  not  warrant  us  in  excluding  the 
idea  that  new  work  and  new  adaptations  may  enlarge  the  motor  field  and 
that  new  functional  co-ordinations,  once  they  become  strongly  constituted 
by  repeated  exercise,  may  represent  a  differentiation  of  labour  in  the 
anatomical  field  concerned. 

The  physiological  researches  of  Sherrington  and  Griinbaum,1  of  Sherring- 
ton,  Mott  and  E.  Schuster,2  agree  with  the  cytotectural  investigations  of 
the  above-mentioned  histologists  in  this  respect  that  they  localise  the  area 
of  general  motility  in  the  ascending  frontal  convolution,  this  area  being 
distinctly  limited  behind  by  the  fissure  of  Rolando,  but  not  well  defined  in 
front.  In  the  gibbon,  which  makes  use  of  its  arms  and  hands,  and  moves 
about  by  preference  on  its  posterior  limbs,  experimental  excitation  of  the 
motor  area  has  shown  a  displacement  downwards  and  forwards  of  the  area 
for  the  movements  of  the  body  and  especially  of  the  eyes.  On  the  other 
hand,  the  motor  area  for  the  movements  of  flexion  and  rotation  of  the  wrist 
extends  to  the  foot  of  the  middle  frontal  convolution.  Histological  investi- 
gation has  confirmed  the  existence  of  the  precentral  intermediate  area  of 
Campbell  and  of  the  areas  defined  by  Brodmann ;  but  the  experimental 
investigations  above  mentioned  go  to  show  that,  in  the  gibbon,  the  inter- 
mediate area  extends  forwards  to  some  considerable  extent,  both  on  the 
external  and  on  the  mesial  surface  of  the  hemisphere,  so  that  the  prefrontal 
area  would  in  this  case  be  reduced  to  a  comparatively  small  region  of  the 
frontal  pole.  Then  again,  if  we  accept  the  findings  of  Brodmann  and 
Campbell,  the  frontal  area,  properly  so  called,  becomes  similarly  much 
reduced,  to  the  advantage  of  the  intermediate  precentral  area.  T?hese 
experiments  of  Sherrington,  Mott  and  Schuster  give  rise  to  considerable 
doubt  because,  if  the  initial  use  of  the  hands  brings  about  such  an  extension 
of  the  intermediate  motor  area  in  the  gibbon,  this  area  should  be  much  more 
extensive  in  the  case  of  man.  In  this  connection,  the  conclusions  arrived 
at  by  Pitres  and  De  Boyer  as  the  result  of  clinical  observations  seem  more 
consistent.  These  authors  limit  the  extension  of  the  motor  area  in  man 

1  Griinbaum.     LOG.  cit. 

2  Schuster.     "  Motor  Localisations  in  the  Brain  of  the  Gibbon,  correlated  with 
Histological  Examination."     Proc.  Roy.  Soc.     1911. 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  63 

to  the  bases  of  the  frontal  convolutions.  The  writer's  personal  observations, 
which  led  him  to  conclude  for  the  existence  of  an  evolutionary  motor  zone,1 
and  the  observations  made  by  surgeons  on  living  patients  (such  as  those  of 
Kocher,2  who  agrees  that  all  the  motor  points  with  the  exception  of  those 
of  the  thumb  and  of  the  shoulder  are  to  be  found  on  the  anterior  Rolandic 
convolution  and  concludes  that  the  chief  point  of  rendezvous  in  the  motor 
region  must  be  the  precentral  sulcus),  warrant  us  in  admitting  a  forward 
extension  of  the  motor  zone. 

This  argument  certainly  applies  to  the  foot  of  the  inferior  frontal  con- 
volution, which  must  still  be  regarded  as  the  motor  zone  of  spoken  language, 
notwithstanding  the  revolutionary  doctrine  of  Pierre  Marie ;  it  is  unnecessary 
from  this  point  of  view  to  make  any  distinction  between  the  functions  of  the 
two  hemispheres.  This  area  is  placed  immediately  in  front  of  the  motor 
zone  for  the  movements  of  the  lips,  face,  tongue,  larynx,  etc. ,  in  front — 
i.e.  of  the  area  for  all  those  groups  of  muscles  employed  in  mastication, 
deglutition,  whistling,  shouting,  etc. 

The  writer  puts  forwards  the  hypothesis  that  the  centre  of  writing,  about 
which  there  has  been  so  much  discussion,  stands  in  relation  to  that  of  the 
arm,  for  movements  of  prehension  and  defence,  just  as  the  centre  of  articulate 
speech  stands  in  relation  to  the  centres  for  mastication,  phonation,  the  facial 
and  lingual  muscles,  etc.  Just  as  the  anterior  portion  of  the  visual  area  can 
be  regarded  as  exhibiting  a  much  higher  grade  of  evolution  as  compared  with 
the  rest  of  the  visual  zone,  so  the  pre-Rolandic  intermediate  area,  considered 
as  a  part  of  the  motor  zone,  may  be  regarded  (eVen  provisionally)  as  an 
evolutionary  motor  zone,  in  the  sense  that  it  represents  the  field  of  extrinsica- 
tion  of  motor  activities  of  a  higher,  more  spiritual  order,  in  men  of  a  more 
advanced  type.  To-day,  notwithstanding  Marie's  brilliant  criticism  of  the 
old  doctrine,  one  can  hold  firmly  to  the  idea  that  the  motor  area  of  articulate 
speech  is  found  on  the  foot  of  the  inferior  frontal  convolution  and  its  neigh- 
bourhood, as,  e.g.,  the  anterior  part  of  the  insula.  I  hold  that  these  are 
areas  in  course  of  evolution  and  they  are  not  differentiated  alike  in  all  men 
nor  do  they  give  fibres  directly  to  the  pyramidal  tract. 

In  writing  we  make  use  of  the  same  limbs  and  the  same  muscles  as  in  the 
coarser  and  more  elementary  movements  requisite  in  the  manifold  needs 
of  life.  The  more  elementary  movements  of  the  upper  limbs  are  those  by 
which  we  take  hold  of  objects  that  are  necessary  for  the  satisfaction  of  the 
corporal  needs  and  the  individual  instincts.  It  is  only  at  a  much  later  period 
in  the  course  of  human  evolution  that  the  progressive  and  specific  functional 
differentiation  for  reading  takes  place  and,  therefore,  this  cortical  field  is  less 
surely  and  generally  established  than  the  cortical  motor  area  of  articulate 
speech. 

The  view  the  writer  here  puts  forward  can  be  aptly  illustrated  by  two 

1  Bianchi.     Lieqoes    sobre    as    Localisaqoes    cerebraes    e    a    Physiopathologia   de 
Linguagem.     Trans,  of  Dr  de  Souza.     Rio  de  Janeiro,  1899. 

2  Kocher.       Hirnerschuttering,      Hirndruck     und     chirurgischen     Eingriffe,     bei 
Hirnkrankheiten,  1901,  and  L'ecorce  cerebrale.     Bonne,  1910. 


64  THE  MECHANISM  OF  THE  BKAIN 

concrete  examples.  Confronted  by  an  enemy,  the  savage  may  employ  a 
club  in  self-defence,  whilst  the  civilised  man  of  to-day,  skilled  in  fencing, 
may,  under  similar  circumstances,  make  use  of  his  sword.  Both  bring  into 
action  the  same  muscles  of  the  right  upper  limb,  and  they  have  the  same 
object  in  view.  The  savage  performs  a  series  of  movements  that  are  coarse 
in  character  and  involve  a  useless  dissipation  of  his  energy.  The  fencer, 
on  the  other  hand,  more  composed,  performs  a  series  of  very  delicate  move- 
ments each  of  which  has  its  raison  d'etre,  movements  that  are  co-ordinated 
.in  due  and  proper  proportion  and  in  perfect  harmony  with  the  two  objectives 
of  offence  and  defence. 

Whilst  the  savage  is  unable,  because  he  has  not  learned  how,  to  perform 
other  movements  more  adapted  for  the  purpose  he  has  in  view,  the  fencer  can, 
if  he  choose,  make  use  of  the  movements  employed  by  the  savage,  although 
he  recognises  the  great  inferiority  and  incoherence  of  these. 

In  the  case  of  the  fencer,  a  differentiation  has  taken  place  in  the  structure 
of  the  cerebral  cortex  of  the  right  upper  limb,  thanks  to  which  a  more  complex 
and  better  co-ordinated  product  is  available. 

Suppose,  now,  the  fencer  lays  aside  the  sword  and  takes  up  the  pen  in 
order  to  describe  his  encounter,  or  let  us  go  further  and  suppose  that  he 
makes  use  of  the  pen  to  attack  his  enemy  or  to  defend  himself  from  the 
attacks  of  the  latter.  Here  we  are  witnesses  of  a  combat  on  a  much  higher 
plane.  What  a  marvellous  cerebral  advancement  is  involved  in  this  process  ! 
How  much  more  delicate  is  the  muscular  co-ordination,  compared  with  the 
movements  of  these  same  muscles  as  employed  by  the  savage  and  the  fencer  ! 

Here  we  must  necessarily  have  the  intervention  of  a  larger  number  of 
co- efficients.  Amongst  these,  the  conceptual  new-formations  and  the 
auditory  and  visual  images  of  the  words,  by  means  of  which  the  writer  seeks 
to  give  expression  to  his  particular  notions,  assume  a  new  importance. 
These  images  are  furnished  by  the  new  cerebral  fields  ;  they  have  no  place 
in  the  movements  of  assault  and  parry  of  the  fencer  and  much  less  in  those 
of  the  primitive  man.  This,  surely,  goes  to  prove  that  to  arrive  at  a  much 
wider  co-ordination  of  movements  and  to  rise  to  a  much  higher  level  of 
functional  dignity  requires  not  only  the  differentiation  of  the  cortical  motor 
centres  themselves,  but  perhaps  also  the  extension  of  the  motor  area  into  a 
field  capable  of  differentiation,  as  well  as  the  indispensable  auxiliary  in  the 
shape  of  other  factors,  or,  as  one  might  say,  the  work  of  special  workmen. 
It  is  a  case  of  division  of  labour  and  co-ordination  of  the  working  forces. 


* 
*  * 


Flechsig  would  have  it  that  in  the  tactile  sphere  we  have  organically 
concentrated  the  centre  of  our  intellectual  existence  in  as  much  as  this  region 
is  in  direct  and  indirect  anatomical  relationship  with  all  the  other  regions 
of  the  cortex,  as  well  as  with  numerous  other  areas  (mostly  centripetal)  which 
come  into  touch  with  it  through  the  intermedium  of  the  optic  thalamus. 
Not  only  does  this  tactile  sphere  serve  as  the  path  for  relations  with  the 
external  world,  in  so  far  as  these  are  established  by  means  of  the  tactile 


EVOLUTION  OF  THE  NERVOUS  SYSTEM  65 

sense,  but,  if  the  author  interprets  Flechsig's  complicated  conception  rightly, 
it  is  only  by  means  of  the  tactile  sphere,  which  embraces  the  sensory  zone 
in  relation  to  the  body,  and  also  the  field  of  innervation  of  the  circulation, 
respiration  and  other  organic  sensations,  that  all  the  other  perceptions  become 
assimilated  with  the  consciousness. 

Bearing  in  mind  the  fact  that  according  to  the  most  recent  investigations 
the  tactile  sphere  embraces  only  the  post-central,  and  does  not  extend  to  the 
precentral,  convolution  (Figs.  1  and  4),  one  can  agree  with  Flechsig  in  regard- 
ing the  tactile  sphere  as  the  field  of  all  the  sensory  impressions  coming  from 
the  organs  composing  our  body  and  that  it  may  consequently  be  the  prin- 
cipal component  in  the  formation  of  the  idea  of  the  ego  or,  in  other  words, 
the  organ  of  the  central  nucleus  of  the  sense  of  individual  existence 
(kinsesthesis) . 

The  author's  pathological  studies  have  induced  him  to  admit,  too,  that 
the  organic  me  is  always  or  almost  always  made  aware  of  and  modified  by 
external  stimuli  no  matter  what  the  area  where  the  relative  image  is  formed. 
In  other  words,  every  perception  is  accompanied  by  a  resonance  in  the 
kinsesthetic  consciousness  and  an  emotional  reflex  of  varying  degree,  a  fact 
which  implies  the  existence  of  direct  and  indirect  anatomical  paths  between 
the  posterior  Rolandic  convolution  and  all  the  other  spheres  of  sensibility. 
We  know  that  the  tactile  sphere — which  in  opposition  to  Flechsig's  view 
is  now  limited  to  the  post-Rolandic  convolution  as  far  as  the  interparietal 
sulcus  behind  and  above,  and,  on  the  interhemispheric  aspect,  to  the  part 
corresponding  to  the  para-Rolandic  lobule — contains  points  excitation  of 
which  causes  modifications  in  the  functions  of  the  viscera,  of  the  circulation, 
respiration,  digestion,  secretions  and  excretions.  It  is  well  established  that 
analogous  modifications  of  these  functions  occur  under  the  influence  of 
more  or  less  powerful  impressions  and  accompany  the  emotions,  inasmuch  as 
all  impressions  furnish,  by  one  path,  the  cognition,  and  by  another  path 
the  awareness  on  the  part  of  the  ego,  of  the  stimulus  which  has  acted  on  the 
senses,  vibrations  of  which  have  reached  the  sensory  fields  of  the  cortex. 
Some  physiologists  and  psychologists  hold  that  emotion  consists  essentially 
in  the  organic  manifestations  of  respiration  and  of  circulation,  those  same 
manifestations  which,  under  the  influence  of  stronger  stimuli,  give  rise  to 
pallor  or  reddening,  to  palpitation  and  respiratory  oppression,  to  dryness 
of  the  mouth,  to  trembling,  the  desire  to  urinate,  etc. 

Further  reference  will  be  made  to  this  question  in  a  succeeding  chapter. 
Meanwhile  we  are  agreed  that  the  nerve- waves  from  every  part  of  the  organ- 
ism are  directed  to  this  organ  or  cortical  area  and  there  become  blended  in 
the  sense  of  individual  existence,  with  attributes  of  well-being  and  strength, 
or  of  malaise  and  weakness,  and  on  it  depend  variations  in  the  tone  of  mind, 
which  may  be  gay  and  active,  or  sad,  irritable  and  negativistic. 

When  all  parts  of  the  organism  perform  their  functions  harmoniously 
the  ego  manifests  interest  in  the  external  world  (activity,  courage).  When, 
on  the  contrary,  any  region  of  the  body  is  diseased  or  out  of  order,  or  all  the 
organs  perform  their  functions  feebly  owing  to  defect  or  alteration  of  the 


66  THE  MECHANISM  OF  THE  BRAIN 

material  intended  for  their  nourishment  and  necessary  for  the  maintenance 
of  life,  a  vague  feeling  of  malaise,  pessimism,  negativism,  discouragement, 
a  prevailing  sense  of  difficulty,  are  significant  of  the  altered  internal  con- 
ditions in  the  vital  sphere.  In  some  illnesses  there  occurs  a  kind  of  dis- 
sociation between  the  percept  and  the  me  which  perceives.  The  author  has 
observed  this  in  some  cases  of  melancholia  and  severe  neurasthenia,  where 
the  kinsesthetic  consciousness,  which  is  the  basis  of  the  afTectivities,  is  quite 
dormant,  so  that  the  patient  perceives  the  external  world  yet  has  no  feeling 
of  an  ego  which  is  perceiving.  For  example,  a  mother  said  to  me  :  "I  see 
my  sons  but  have  no  longer  any  feeling  for  them.  I  seem  to  be  another 
person  and  this  causes  me  great  distress."  Other  patients  are  capable  of 
identifying  their  ego  historically  yet  maintain  that  they  do  not  feel  they  are 
perceiving  although  they  recognise  objects  and  persons,  and  this  causes 
them  much  concern.  This  condition  induces  in  some  a  true  metamorphosis 
of  the  individual  personality.  One  lady,  whose  story  I  have  given  in  my 
Text  Book  of  Psychiatry?  said  to  me  :  "  I  seem  to  recognise  you  as  Professor 
B.  but  I  am  not  the  Mrs  A.  whom  you  say  I  am.  .That  lady  does  not  exist 
and  I  who  am  speaking  have  no  existence,"  etc.  In  this  state  one  must 
recognise  something  akin  to  a  profound  sleep  of  the  organic  ego  which  is 
the  nucleus  of  the  personality  and  normally  should  receive  notice  of  all 
sensory  processes  occurring  in  the  other  areas  of  the  cortex,  but  in  the  cases 
under  consideration  these  products  fail  to  be  linked  up  with  the  irresponsive 
ego.  Here  we  have  a  state  of  paresis  of  the  cortical  field  of  the  kinsesthesis. 
The  ego  is  profoundly  modified  and  loses  its  historical  bearings  owing  to  a 
break  in  continuity.  The  cortical  fields  of  the  other  senses  are  in  active 
working  order  but  their  products  are  missing  links  in  the  chain  of  historical 
continuity  provided  by  the  somatic  ego,  because  the  latter  fails  to  identify 
them. 

If  we  have  succeeded  in  proving  that  the  conception  of  a  great  occipito- 
parieto- temporal  intellectual  centre,  in  the  sense  of  Flechsig,  is  not  tenable 
and  are  agreed  that  this  region  should  be  regarded  as  an  extensive  area  of 
evolution  of  the  primary  sensory  areas,  visual,  auditory  and  tactile,  and 
that  these  preserve  their  functional  individuality  and  their  respective  char- 
acteristics, we  are  in  a  position  to  attack  the  problem  of  the  function  of  the 
frontal  lobe. 

What  does  this  very  conspicuous  part  of  the  neopallium  represent  in  the 
evolution  of  the  brain  ?  What  part  does  it  play  in  the  harmony  of  the 
cerebral  activity  ? 

1  Bianchi.  Trattato  di  Psichiatria.  1st  and  2nd  edit.  Naples,  1915.  Eng. 
Trans.,  1906. 


CHAPTER  II 

History  and  Evolution  of  the  Doctrine  Concerning  the 
Functions  of  the  Frontal  Lobes 

THE  question  now  to  be  confronted  is  one  of  the  most  abstruse  and  debated 
in  cerebral  physiology  or,  rather,  in  anatomical  psychology.  The  function 
of  the  extensive  cortical  field  situated  in  front  of  the  motor  zone  has  given 
rise  to  one  of  the  very  keenest  discussions.  The  problem  can,  and  should,  be 
stated  in  precise  terms.  Does  the  anatomical  substratum  of  the  psychic 
processes  consist  exclusively  of  the  sensory  and  motor  areas  and  the  language 
areas,  or  are  there  other  cortical  areas  which,  whilst  neither  sensory  nor 
motor  nor  organs  of  language,  yet  co-operate  in  a  particular  manner  towards 
the  formation  and  development  of  thought  and  the  psychic  personality  ? 
These  were  the  terms  in  which  the  writer  put  forward  the  problem  in  his 
first  communication  on  this  subject  to  the  National  Congress  of  Medicine 
in  Rome,  1892,  when  he  introduced  a  discussion  on  the  functional  localisa- 
tions of  the  cerebral  cortex,1  and  afterwards  to  the  International  Congress  at 
Rome  in  1894,  and  they  were  surely  sufficiently  explicit  to  have  prevented 
any  misunderstanding.2 

In  the  preceding  pages  we  have  mentioned  Flechsig's  attempt  (which 
seemed  for  a  time  to  have  succeeded  completely)  to  assign  the  highest 
functions  of  association  and  mental  syntheses  to  the  great  temporo-parieto- 
occipital  area,  and  we  have  demonstrated  that  Flechsig's  doctrine  does  not 
accord  with  fact.  These  areas  are  the  anatomical  substratum  that  is  gradu- 
ally developed  through  perceptions  and  processes  of  perceptual  differentiation 
and  they  represent  organs  for  the  perfecting  of  products  from  simpler 
processes. 

From  ancient  times  anatomists,  physiologists  and  poets  have  spoken  of 
the  frontal  lobes  as  the  organ  of  intelligence. 

The  doctrines  of  Gall  and  Spurzhein,  which  Huf eland,  though  a  strong 
opponent,  declared  to  be  "  the  most  important  event  of  the  eighteenth 
century  (Soury)  and  one  of  the  boldest  and  most  conspicuous  advances  in 
the  domain  of  natural  science,"  can  be  condensed  in  the  following  proposi- 
tions :  (1)  the  cerebral  convolutions  and  especially  the  grey  substance  are 
the  organs  of  the  intellectual  faculty  and  should  be  recognised  as  "  the  parts 
where  the  instincts,  sentiments,  tendencies,  talents,  affective  qualities  and, 
in  general,  the  moral  and  intellectual  forces,  are  exercised."  (2)  There  exist 
particular  forms  of  intelligence,  memory,  imagination,  and  tendencies,  and 

1  Bianchi.     Atti  del  Congresso  delta  Societa  Italiana  di  Medicina  interna.     1892. 

2  Bianchi.     Atti  del  Congresso  Internazionale  di  Medicina  e  Chirurgia  in  Roma. 
1894. 

67 


68  THE  MECHANISM  OF  THE  BRAIN 

each  cerebral  organ  has  its  own  particular  intelligence,  memory,  imagination, 
etc.  (3)  "  The  qualities  common  to  man  and  to  animals  have  their  seats  in 
the  lateral  and  posterior  parts  of  the  head  (brain) .  In  proportion  as  animals 
have  been  endowed  with  a  share  of  certain  anterior  and  superior  encephalic 
parts,  so  they  enjoy  certain  intellectual  faculties.  In  man,  when  the  organs 
of  the  posterior  and  inferior  part  of  the  brain  are  excessively  developed  and 
those  of  the  anterior  superior  portion  are  compressed,  the  animal  inclinations 
must  have  the  ascendancy.  .  .  .  Man  is  the  more  intelligent,  the  more  the 
anterior  superior  brain  is  developed/'1  This,  of  course,  is  an  intuitive, 
subjective  manner  of  regarding  the  part  played  by  the  anterior ''brain  in  the 
extrinsication  of  life,  but  one  cannot  deny  that  the  proposition  contains  a 
germ  of  truth,  since  later  clinical  and  experimental  researches  have,  to  a 
certain  extent,  confirmed  the  proposition  in  a  general  way. 

The  work  of  Gall  and  Spurzhein  was  much  exalted  by  Flechsig,  but 
there  was  one  other  part  of  the  doctrine  which  had  also  a  foundation  of  truth, 
and  survives  to-day,  as  mentioned  by  that  ardent  student  of  neurology, 
Ireland 2 — viz.  the  localisation  of  the  faculty  of  language  in  the  orbital  part 
of  the  anterior  lobe. 

According  to  Burdach  3  the  frontal  lobes  would  be  related  particularly 
with  psychic  activity  and  objective  cognition.  He  had  observed  the  feeling 
of  tension  (already  noted  by  Lancisi,  who  had  designated  the  frontal  lobes 
as  the  factory  of  thought)  in  the  frontal  region  when  thought  is  intense. 
He,  too,  attributed  a  great  importance  to  the  particular  form  of  the  forehead 
in  relation  to  the  intellectual  faculty  and  maintained  that  the  two  poles  of 
the  brain,  anterior  and  posterior,  do  not  act  independently  but  manifest 
a  common  activity,  because  "  in  cognition  we  have  predominating  at  one 
time  objectivity,  at  another  time  subjectivity." 

Fleurens4  cast  these  notions  aside  as  fantastical,  and  maintained  that 
"  there  is  no  such  thing  as  a  different  site  for  the  different  faculties  and  the 
different  perceptions."  The  faculty  of  perceiving,  or  judging,  or  willing  one 
thing  resides  in  the  same  locality  which  perceives,  judges,  and  wills  another. 
According  to  this  view,  there  would  be  no  differentiation  in  the  cerebral 
mantle  for  different  sensations,  so  that  destruction  of  any  one  part  of  the 
cortex  would  lead  to  weakening  of  all,  and  it  would  follow  that  all  the  in- 
tellectual faculties,  all  the  perceptions,  all  the  instincts,  constitute  essentially 
one  single  faculty,  for  they  would  reside  in  the  same  organ  and  occupy  the 
same  site.  True,  Fleurens  distinguished  the  organ  which  perceives  and 
wills  from  that  which  co-ordinates  and  that  which  excites,  but  these  organs 
were  respectively  the  cerebral  hemispheres,  the  cerebellum  and  the  spinal 
medulla,  with  its  nerves.  That  doctrine  is  now  a  thing  of  the  past. 

1  Jules  Soury.     Le  systeme  nerveux  central.     Paris,  1899. 

2  Ireland.     Journ.  of  Mental  Science.     1898. 

3  Soury.     Loc.  cit.  and  Baue  u.  Leben  des  Gehirns.     Leipzig,  1819-1826. 

4  Fleurens.      Recherches    experimentales    sur    Us   proprietes   et    Us  jonctions    du 
systeme  nerveux  dans  Us  animaux  vertebres.     Paris,  1842.     2nd  edit. 


THE  FRONTAL  LOBES  69 

Gratiolet 1  was  strongly  opposed  to  the  doctrine  of  the  localisations,  yet, 
in  the  light  of  to-day,  when  we  review  the  results  of  clinical  and  experi- 
mental researches  and  the  debates  upon  the  views  advanced  by  Broca 
concerning  the  localisation  of  language,  he  appears  as  one  of  the  founders  of 
the  doctrine  of  localisations.  He  admitted  the  possibility  of  "  supposing 
the  cerebral  hemispheres  to  be  divided  into  as  many  different  regions  as 
there  are  organs  of  different  sensations  in  the  periphery,"  also  "the  possi- 
bility of  allocating  a  memory  and  an  imagination  ' '  to  each  of  these  brains  ; 
and  although  he  was  prepared  to  admit  the  likelihood  of  a  seat  for  the 
"  reason  which  commands  "  and  to  recognise  in  the  frontal  lobe  "  the  majesty 
of  the  human  brain  "  he  supported  the  doctrine  of  Fleurens,  especially  because 
he  found  it  difficult  to  understand  why  there  should  be  so  many  cerebral 
organs.  "  Of  what  assistance  would  one  be  to  the  other  ?  How  would  the 
brain  of  the  ear  be  able  to  come  to  the  aid  of  the  brain  of  the  eye  ?  "  With 
good  reason,  he  assigned  great  importance  to  the  centrum  ovale  because  here, 
if  anywhere,  "  the  functional  synergy  of  the  brain  could  find  its  anatomical 
condition — viz.  in  the  multiple  commissures  which,  uniting  together  all  the 
convolutions  of  one  hemisphere  in  the  most  complex  manner,  prove  to  the 
hilt  the  functional  unity  of  the  brain."  Gratiolet  was  undoubtedly  possessed 
of  superior  judgment  and  great  penetrative  capacity,  but  he  was  unable  to 
cast  aside  the  old  prejudice  that  favoured  the  doctrine  of  the  unity  of  thought. 
It  is  to  his  credit,  however,  that  he  recognised  the  various  possibilities, 
objective  proofs  of  which  have,  since  his  time,  come  to  hand. 

Experimental. and  clinical  investigations  have  now  overcome  the  barrier 
of  prejudice  which  confronted  all  attempts  to  found  a  psychology  based  on 
the  anatomy  of  the  brain.  As  an  example  of  this  prejudice  one  may  cite  the 
statement  of  Lelut,2  who  wrote :  "  The  question  of  the  relations  to  be 
established  between  the  brain  and  the  higher  acts  of  thought  is  very  obviously 
one  of  those  questions  condemned  by  their  very  nature  to  perpetual  in- 

determination. " 

• 
•f 

To  Hitzig  must  be  given  the  credit  of  having  placed  the  question  upon  an 
experimental  basis.  Starting  out  with  the  data  of  comparative  anatomy 
bearing  on  the  evolutionary  parallelism  between  the  frontal  lobes  and 
intelligence,  he  initiated  experiments  on  higher  mammals  which  confirmed 
the  supposition  previously  deduced  from  the  literature  of  the  subject  and 
from  comparative  anatomy — viz.  that  the  frontal  lobes  were  really  the  seat 
of  the  higher  mental  faculties.3  It  also  stands  to  the  credit  of  Hitzig  that, 
in  his  controversy  with  the  German  physiologists,  Munk  and  Goltz,  he  was 
able  to  bring  forward  experimental  proof  of  the  facts  that,  in  dogs,  removal 
of  the  frontal  lobes  was  never  followed  by  any  motor  disturbance,4  and,  in 

1  Gratiolet.     Observations  sur  la  forme  et  le  poids  du  cerveau.     Paris,  1861. 

2  Lelut.     "  Formule  des   rapports  du  cerveau  a  la  pensee."      Annales  medico - 
psychologiques.     1843. 

3  Hitzig.      Untersuckungen  uber  das  Gehirn.     1874. 

4  Hitzig.     "  Achto  Wander  versammlung  d.  W.  D.  Neurologen."     N euroloyisches 
Centralb.     1883. 


70  THE  MECHANISM  OF  THE  BRAIN 

monkeys,  resulted  in  loss  of  recent  acquisitions  and  those  that  were  the 
result  of  training. 

In  1884,  in  his  dispute  with  Munk  and  Goltz,  Hitzig  l  wrote  as  follows  :— 
"  I  adhere  to-day  to  the  hypothesis  I  put  forward  in  1870  that  the  cortical 
centres  are  merely  collecting  centres.  I  can  support  the  opinion,  which  has 
often  been  expressed,  that  deep  or  very  extensive  lesions  affecting  the  central 
mechanism  necessarily  interrupt  a  multitude  of  bundles  which  unite  different 
cortical  regions  of  the  brain  with  one  another,  and  must  consequently  give 
rise  to  symptoms  that  are  susceptible  to  a  relatively  rapid  improvement. 
To  this  category  belong  the  transitory  disturbances  of  sight  which  follow 
deep  lesions  affecting  different  regions  of  the  hemispheres.  I  find  myself  in 
opposition  to  Munk  as  regards  the  nature  of  the  higher  intellectual  functions 
and  their  relations  with  the  anatomical  substratum.  Munk  holds  that 
there  are  no  such  things  as  special  organs  for  these  functions  and  that  there 
is  no  necessity  for  them.  I  believe  with  him  that  intelligence,  or  more 
correctly,  the  treasury  of  ideas,  is  to  be  sought  for  in  all  parts  of  the  cortex, 
or  rather,  in  all  parts  of  the  brain  ;  but  I  hold  that  abstract  thought  must  of 
necessity  require  particular  organs  and  those  I  find  in  the  frontal  brain." 

Ferrier,2  contemporaneously  with  Hitzig  and  perhaps  even  before  him, 
attacked  the  question  of  functional  localisations  by  means  of  experiments 
on  higher  mammals.  In  the  first  edition  of  his  wTork  he  located  the  centre 
for  movements  of  the  head  and  eyes  in  the  frontal  lobes  and  attached  great 
importance  to  these  movements  in  attentive  attitudes,  regarding  them  as  an 
essential  part  of  attention.  He  makes  the  frontal  lobes  the  organ  of 
attention,  and  so  we  can  regard  him  as  having  arrived,  by  a  different  path, 
in  the  company  of  those  who  attribute  a  higher  psychic  function  to  the 
frontal  lobes. 

In  the  second  edition  of  his  book  Ferrier  reaffirms  the  view  that  in 
perception  there  is  included  a  muscular  element,  which  plays  its  part  in 
the  re- awakening  of  the  correlative  idea.  When  we  recall  particular  ideas  to 
memory,  we  really  execute,  in  a  more  or  less  suppressed  manner,  the  move- 
ments with  which  these  ideas  are  respectively  associated  in  a  form  of  organic 
cohesion.  In  representing  a  thought  we  reproduce,  in  a  more  or  less  rudi- 
mentary manner,  the  articulatory  movements  involved  in  the  words  in 
which  the  thought  has  been  symbolised.3  In  the  same  way,  just  as  our 
attention,  when  attracted  by  an  object,  determines  an  accommodation  of  the 
eyes,  associated  with  such  movements  of  the  head  as  serve  to  bring  the 
object  on  the  central  point  of  the  retina,  so,  when  engaged  in  attentive 
ideation,  we  are  making  precisely  the  same  movements  of  the  head  and  eyes 
as  are  necessary  for  clear,  actual  vision.  "...  Destruction  of  the  frontal 
lobes  according  to  the  degree  of  its  complexity  impairs  or  paralyses  the 

1  All  Hitzig's  works  and  the  relative  disputes  were  collected  in  one  volume — 
Untersuchungen  uber  das  Gehirn.     1904. 

2  Ferrier.     The  Functions  of  the  Brain.     1877. 

3  Strieker.     Du  langage  et  de  la  musique.     1885. 


THE  FRONTAL  LOBES  71 

lateral  movements  of  the  head  and  eyes.  Although  some  ocular  move- 
ments may  be  excited  reflexly  by  retinal  impressions,  there  appears  to  be 
loss  of  power  of  locating  or  directing  the  gaze  towards  objects  which  do  not 
fall  spontaneously  within  the  field  of  vision.  Correlative  with  this  immobility 
of  the  head  and  eyes  there  is*  the  aspect  of  uninterest  and  stupidity,  the 
absence  of  that  active  curiosity  which  is  normally  manifested  by  monkeys, 
and  the  mental  degradation  which  seems  to  depend  on  the  loss  of  the  faculty 
of  attention  and  all  that  it  implies  in  the  sphere  of  intellectual  operations."  L 

Ferrier  accordingly  makes  the  frontal  lobes  a  centre  for  the  movements 
of  the  head  and  eyes,  which  are  the  motor  equivalents  of  attention.  These 
results  were  confirmed  in  part  by  Griinbaum  and  by  Sherrington,2  who,  in 
the  brain  of  the  chimpanzee,  more  especially  at  the  posterior  extremity  of 
the  middle  frontal  convolution,  found  a  frontal  area,  electric  stimulation 
of  which  induced  movements  of  the  eyes. 

In  point  of  fact,  observation  of  animals  deprived  of  their  frontal  lobes 
shows  that  movements  of  the  head  and  eyes  persist  in  all  respects,  neither 
more  nor  less,  just  as  we  find  them  in  human  imbeciles.  In  the  case  of 
monkeys  it  is  only  during  the  first  few  days  after  the  operation,  when  the 
lesion  falls  too  near  the  motor  zone  or  directly  affects  the  motor  area  of  the 
muscles  of  the  head  and  trunk,  that  motor  disturbances  along  with  a  certain 
fixity  of  the  gaze  are  observed.  After  days  or  weeks  these  symptoms  dis- 
appear, so  that  the  absence  of  that  active  curiosity  normally  exhibited  by 
monkeys  cannot  be  the  result  of  paralysis  of  these  movements  which,  after 
all,  are  the  somatic  elements  necessary  in  the  attentive  process,  but  rather 
the  effect  of  a  particular  mental  condition  which  will  be  dealt  with  in  a 
subsequent  chapter. 

The  author's  first  experiments  on  dogs  warranted  the  opinion  he/expressed 
at  the  time3  that  unilateral  destruction  of  the  prefrontal  lobe  of  the  dog 
was  not  followed  by  any  noteworthy  symptom,  whilst  bilateral  destruction 
brought  into  evidence  a  distinct  alteration  of  character,  marked  especially 
by  weakening  of  all  the  psychic  manifestations :  defect  in  perceptive 
judgment ;  exaggerated  fear,  resulting  from  defective  critical  capacity  and 
inability  to  make  use  of  the  physical  powers  although  these  were  well 
preserved  ;  amnesia  and,  generally  speaking,  a  psychically  blind  behaviour  ; 
defect  in  initiative  and  resource  ;  lack  of  finality  in  the  complex  movements, 
as  betrayed  by  incoherent  conduct  and  diminished  vivacity  (lowering  of  the 
psychic  tone).  In  fact,  any  ordinary  individual  would  have** classed  these 
dogs  as  weak-minded. 

How  were  these  phenomena  to  be  interpreted  in  the  light  of  the  then 

1  Ferrier.      The  Functions  of  the  Brain.     2nd  edit.      1887. 

2  Sherrington.      "  Observations  on  the  Physiology  of  the  Cerebral  Cortex  of  some 
of  the  Higher  Apes."     Proc.  Roy.  Soc.     1901. 

3  Bianchi.     "  1st    die    Vermmft    eine    auschliesslich    den  Empfindungsbereichen 
der    Hirnrinde    zukommende    Thatigkeit  ?  "      Untersuchungen    zur    Naturlehre    des 
Menschen  und  der  Tiere  ;  herausgegeben  vom  Moleschott.     Bd.  xix.,  Heft  4. 


72  THE  MECHANISM  OF  THE  BRAIN 

current  knowledge  ?  The  sensory  areas  had  escaped  injury.  The  associa- 
tive fibres  running  between  them  and  between  the  two  hemispheres  had  not 
been  interrupted  at  any  point.  The  sensory  functions,  including  the  tactile, 
were  preserved  intact,  as  were  also  the  movements.  Yet  the  dog  in  question 
had  suffered  no  small  damage  to  its  psychic  life  !  The  author's  explanation 
ran  thus  :  "We  are  bound  to  admit  that  the  process  of  perception  is  the 
product  of  the  co-ordination  of  indispensable  elementary  factors,  which 
cannot  separately  furnish  the  concrete  images  of  objects,  no  matter  what 
sensory  apparatus  is  involved.  The  co-ordination  of  simple  perceptions, 
either  actual  or  representative,  by  means  of  associative  paths  and  laws, 
gives  rise  to  more  complex  products,  the  intellectual  exponent  of  which, 
in  man,  augments  enormously,  up  to  the  highest  abstract  conceptions,  which 
are  the  outcome  of  still  vaster  co-ordinations.  Now,  I  believe  it  is  permissible 
to  suppose  that  this  vast  co-ordination,  whence  result  the  finality  of  conduct 
and  the  homogeneity,  to  use  a  Spencerian  phrase,  has  its  seat  in  an  organ 
distinct  from  the  organs  of  perception." 

In  support  of  this  view  the  author  adduced  the  example  of  the  progressive 
complication  of  the  reflexes.  The  stimulus  which  reaches  the  cells  in  the 
posterior  cornua  of  the  spinal  cord  and,  without  proceeding  further,  finds 
resolution  in  a  simple  reflex  movement,  furnishes  an  example  of  co-ordination. 
The  passage  of  the  stimulus  from  the  lower  to  higher  stations  such  as  those 
in  the  mid-brain,  and,  still  higher,  in  the  optic  thalamus,  and  the  much  more 
complicated  and  co-ordinated  movements  which  result  therefrom,  provide 
examples  of  other  co-ordinations  which  are  effected  in  organs  that  are  quite 
distinct  from  the  preceding,  and  at  the  same  time,  much  more  complex. 
This  being  so,  there  were  grounds  for  the  argument  that  the  more  extensive 
associations,  the  more  delicate  co-ordinations  of  the  sensory  products  whence 
result  the  complex  conceptions  which  resolve  themselves  into  conduct  (in 
the  broad  sense  of  the  term),  possess  their  own  particular  organ,  of  recent 
evolution,  in  close  and  immediate  relation  with  all  those  others  that  have 
to  furnish  it  with  the  sensory  material  which  it  is  destined  to  elaborate. 
"  This  organ  would  be  to  the  sensory  and  motor  centres  what  these  are  to  the 
optic  thalamus  and  subcortical  nuclei,  and  these  in  turn  to  the  spinal  cord. 
The  natural  history  of  the  evolution  of  the  nervous  system  throughout  the 
whole  animal  series  testifies  to  the  probable  truth  of  my  argument." 

In  an  article  published  in  Brain,1  1895,  the  author  gave  the  results  of  a 
series  of  experiments  he  had  performed  on  dogs  and  monkeys  which  were 
shown  to,  and  examined  by,  the  members  of  a  committee  of  the  International 
Congress  of  Medicine  held  at  Rome  in  1894.2  The  findings  were  summarised 
as  follows  : — 

1.  Restlessness  and  inquietude  of  the  animals  which  had  suffered  mutila- 
tion of  both  frontal  lobes.  The  animals  were  always  moving  about 
aimlessly,  hither  and  thither. 

1  Bianchi.     "  The  Functions  of  the  Frontal  Lobe."     Brain.     1895. 

2  Bianchi.     Attidel  Congresso  Internazionale  di  Medi'ina  e  Chirurgia.    Roma,  1894. 


THE  FRONTAL  LOBES  73 

2.  Suppression  of  curiosity  and  of  the  attitudes  of  observation  so  common 

in  monkeys,  and  hence  a  certain  degree  of  indifference  to  all  that 
occurred  or  existed  in  their  surroundings. 

3.  Defect  of  a^ectivity  towards  other  monkeys  and  other  animals,  and 

also  towards  persons  in  whom  they  had  manifested  a  lively  interest 
prior  to  operation. 

4.  Greater  emotivity,  especially  a  strange  fear  induced  by  noises,  or  by 

the  sight  of  other  animals,  such  as  a  dog,  the  presence  of  which  prior 
to  the  operation  did  not  at  all  disturb  the  monkey,  and  difficulty 
in  restoring  a  state  of  calm  (result  of  decadence  of  the  power  of 
criticism  and  of  the  perceptive  capacity). 

5.  Defect  of  reflection,  judgment  and  memory,  and  an  incapacity  for 

new  adaptations. 

6.  Weakening  of  certain  instincts. 

7.  Stereotypisms  and  automatisms. 

These  findings  have  been  confirmed  by  other  investigators  but  they  have 
also  met  with  a  good  deal  of  severe  criticism,  to  which  attention  will  be 
directed. 

When  we  say  that  intelligence  or,  rather,  mind,  as  Hitzig  put  it,  is  not  a 
function  of  the  whole  brain  (in  the  sense  of  Fleurens) ,  and  that  some  psychic 
functions  depend  upon  particular  regions  of  the  cerebral  cortex  that  have 
been  more  or  less  well  defined,  we  lay  ourselves  open  to  criticism.  The  writer 
agrees  with  Munk,^>  he  /already  clearly  stated  in  his  first  communication, 
that  the  entire*  Hrain  contributes  to  the  formation  and  extrinsication  of 
intelligence,  not  in  the  sense  of  Fleurens,  but  in  the  sense  of  a  division  of 
labour  between  the  various  cortical  areas,  and  of  a  co-ordination  and  associa- 
tion of  the  various  products  on  the  part  of  a  particular  cerebral  organ. 
This  notion  harmonises  with  all  the  data  that  have  been  furnished  both  by 
experimental  investigation  and  by  clinical  observation. 

The  writer  has  never  asserted  that  the  frontal  lobe  is  the  organ  of  the 
intellect.  What  he  did  say  was  that  it  is  an  organ  of  intellect  and  that  the 
work  of  the  entire  brain  contributes  to  this,  its  highest  manifestation.  He 
expressed  the  problem  in  terms  that  were  quite  clear  and  distinct.  It 
may  be  put  as  follows : — Does  there  exist  a  cerebral  organ  which  has  the 
faculty  of  utilising  the  mental  products  of  the  sensory  areas  of  the  cortex 
for  the  construction  of  mental  syntheses  more  suited  for  the  spiritualisation, 
and  hence  the  cognition,  of  nature,  an  organ  giving  rise  to  reactions  upon  the 
world  which,  on  the  basis  of  individual  and  collective, experience,  permit  a 
higher  adaptation  of  the  individual  to  his  physical  and  social  environment, 
an  organ  which  renders  possible  the  lyifqlding  of  a  long  process  of  logically 
connected  thought  ?  '  -  " 

There  was  no  ground  for  the  misconstruction  put  upon  the  author's 
views.  In  the  article  referred  to  in  Brain,  page  519, 1  apropos  of  the  formation 
of  the  psychic  personality,  will  be  found  these  words :  "  The  whole  of  the 

1  Bianchi.  Loc.  cit. 


\ 

74  THE  MECHANISM  OF  THE  BRAIN 

nervous  system  takes  part  in  it  "  ;  and  on  page  521  :  "my  hypothesis  is 
that  the  frontal  lobes  are  the  seat  of  co-ordination  and  fusion  of  the  incoming 
and  outgoing  products  of  the  several  sensory  and  moto1,'  areas  of  the  cortex." 
Those  who  quote  the  author  as  having  said  that  the  frontal  lobes  are  the 
organs  of  intelligence  make  a  great  mistake  and  distort  an  idea  that  was 
expressed  clearly  and  precisely. 

Munk 1  and  Goltz  have  taken  a  very  prominent  part  in  the  debate 
on  this  subject,  and  both  authorities  have  ranged  themselves  against  the 
doctrines  formulated  by  Hitzig. 

Munk  strongly  opposes  the  views  both  of  Hitzig  and  of  Ferrier  and 
maintains  that  there  are  no  relations  subsisting  between  intelligence  and  the 
frontal  lobes  any  more  than  with  any  other  region  of  the  brain.  In  his 
opinion,  the  disturbances  of  intelligence  that  follow  extensive  lesions  of  the 
two  occipital  lobes  are  incomparably  more  severe  than  those  that  occur  after 
removal  of  the  frontal  lobes.  In  one  of  his  works  he  writes  :  "  Intelligence 
has  its  seat  everywhere  in  the  cortex  of  the  brain  and  in  no  part  in  particular. 
It  is,  in  effect,  the  sum  and  resultant  of  all  the  images  or  representations 
derived  from  sensory  perceptions.  Any  lesion  of  the  cerebral  cortex  what- 
soever alters  the  intelligence,  all  the  more  severely  the  more  extensive  the 
lesion,  and  this  is  always  due  to  the  loss  of  its  groups  of  images  or  representa- 
tions, simple  and  complex,  which  had  their  foundations  in  the  perceptions 
that  belong  to  the  injured  cortical  area.  The  intellectual  disturbance  will 
be  definite  if  :  (1)  the  perceptive  elements  are  destroyed  ;  (2)  there  remains 
no  more  substance  which  can  become  the  new  seat  of  the  notions  lost. 
Blindness,  deafness,  and  motor  paralysis,  complete  or  incomplete,  produce, 
each  on  its  own  account,  a  restriction  of  the  field  of  intelligence,  and,  if 
several  areas  are  injured  at  one  and  the  same  time,  the  intellectual  breadth 
and  activity  diminish  all  the  more  with  the  restriction  of  the  field  of  the 
remaining  notions,  whilst  there  is  an  increasing  obstacle  to  the  formation 
of  new  ideas,  so  that  sooner  or  later  the  animal  appears  to  us  as  though  it 
were  affected  by  imbecility."  One  cannot  find  fault  with  Munk  sb'far  as 
dogs  are  concerned,  but  one  cannot  agree  with  him  when  he  states  that  in 
man,  as  well  as  in  monkeys,  the  region  (cortical)  of  the  nape  of  the  neck  has, 
to  a  great  extent,  the  same  functions  as  the  frontal  lobe. 

Munk  found  that  he  could  excite  the  frontal  lobe  by  means  of  the  faradic 
current,  and  so  attributed  to  it  a  senso-motor  function,  controlling  the  nape 
of  the  neck  and  trunk.  Hitzig,  on  the  other  hand,  found  the  frontal  lobe 
could  not  be  excited,  and  with  good  reason  blamed  Munk  for  having  used 
too  strong  currents.  Hitzig,  again,  admitted  having  met  with  visual  dis- 
turbances on  mutilation  of  the  frontal  lobes,  a  finding  confirmed  by  Goltz. 
Munk,  however,  excluded  this  and  stated  that  he  had  never  observed  it. 
The  truth  is  that  in  the  dog  the  frontal  lobe  is  still  relatively  small,  and 
electric  currents  of  even  moderate  strength  excite  the  neighbouring  sigmoid 

1  Munk.  Uber  die  Functionen  des  Grosshirnrinde ,  ecc.  1890.  (Many  of  Munk's 
communications  on  the  functional  localisation  of  the  brain,  up  to  1890,  are  collected 
in  this  volume.) 


THE  FRONTAL  LOBES  .  75 

gyms  and  the  area  for  the  musculature  of  the  neck  and  trunk,  unless  strict 
precautions  are  taken. 

Munk  l  extends  what  he  called  the  Fuhlsphare  (feeling  sphere)  to  the 
frontal  lobe  and  locates  there  the  centres  for  the  muscles  of  the  nape  of  the 
neck  and  trunk,  maintaining  that  motor  paralysis  of  the  muscles  of  the  trunk 
follows  mutilation  of  the  frontal  lobes  in  dogs,  so  that  the  animals  were 
unable  to  turn  to  the  paralysed  side.  The  results  of  the  author's  experiments 
on  monkeys  are  in  direct  opposition  to  this  finding.  In  dogs,  this  symptom 
is  only  present  at  the  beginning,  or  when  a  part  of  the  sigmoid  gyrus  has 
been  excised.  When  a  lesion  is  bilateral,  the  deviation  of  the  trunk  and  the 
circus  movements  are  of  brief  duration  and  towards  the  more  injured  side. 
In  these  cases,  along  with  the  circus  movements,  which  tend  to  disappear, 
there  are  also  mental  disturbances  or  changes  in  the  character  and  conduct 
of  the  animals  operated  upon,  features  observed  also  by  Goltz.  The  insistent 
affirmations  of  Munk  were  severely  criticised  by  Ferrier,  Goltz,  Bechterew, 
and  by  Shepherd,  who  declared  that  in  the  monkeys  and  cats  on  which  he 
had  experimented  he  found  no  disturbance  of  the  muscles  of  the  trunk. 
The  cats  could  jump  and  run  about,  and  the  monkeys  walk  and  climb, 
precisely  as  they  did  before  they  underwent  the  mutilation  of  the  frontal 
lobes. 

That  the  views  of  Grossglick,  Munk,  Luciani  and  others,  who  have 
maintained  that  the  frontal  lobes  are  the  centres  for  the  musculature  and 
the  sensibility  of  the  nape  of  the  neck  and  of  the  back,  are  erroneous,  has 
been  amply  proved  by  unprejudiced  and  reliable  observers.  It  is  certainly 
a  fact  that  even  strong  excitation  of  the  area  in  question,  in  monkeys,  is 
rarely  followed  by  movements  of  the  neck,  even  when  the  state  of  narcosis 
in  the  animal  operated  upon  is  very  light.  It  is  to  be  added  that  destruction 
of  this  area  never  gives  rise  to  prominent  disturbances  of  sensibility  in  the 
limbs,  the  neck,  the  trunk,  or  the  head,  much  less  to  permanent  limitation 
of  movements.  Werner  2  maintains  that  strong  and  prolonged  currents  are 
necessary  in  order  to  excite  the  frontal  lobe,  and  he  blames  other  investi- 
gators for  having  employed  very  weak  currents,  and  so  having  arrived  at 
what  he  considered  to  be  an  erroneous  conclusion  regarding  the  inexcitability 
of  the  frontal  lobe.  In  this  respect  Werner  commits  an  undoubted  error  in 
technique,  and  the  absurdity  of  the  position  he  takes  up  is  proven  by  the 
fact  that  the  prolonged  application  of  strong  currents  to  any  part  whatsoever 
of  the  brain  gives  rise  to  disturbances  at  a  distance,  for  very  obvious  reasons. 
Werner  ought  to  come  into  line  with  Unverricht.3  This  investigator  pro- 
voked an  epileptic  attack  by  means  of  prolonged  and  severe  excitation  of 
the  occipital  lobe,  similar  to  what  took  place  when  he  excited  the  motor 
zone.  The  convulsive  attack  was  caused  by  excitement  in  the  motor  area 

1  Munk.     Sitzungsber.     Berlin  Akademie.d.^Wissensch.     1889-1896. 

2  Werner.     "  tlber  elektrische  Reizversuclie  in  der  Rumpf  und  Nackenregion  d. 
Grosshirns  beim  Hunde."     Allgemeine  Zeitschrift  f.  Psych.     1895.     Vol.  lii. 

3  Unverricht.       "  Experimentelle     und     klinische     Untersuchungen     iiber     die 
Epilepsie."     Arch.  f.  Psychiatric  u.  Nerventer.     Bd.  xiv. 


76  THE  MECHANISM  OF  THE  BRAIN 

produced  from  a  distance  by  a  powerful  current  applied  to  the  occipital  lobeJ 
Many  years  ago,  Penta  and  the  author  repeated  Unverricht's  experiments 
with  confirmatory  results.  The  test  consisted  in  making  a  deep  incision 
into  the  cerebral  hemisphere  between  the  point  excited  and  the  sigmoid 
gyrus  (the  epilepto- genetic  centre  in  dogs,  according  to  Albertoni),  immedi- 
ately the  first  contractions  characteristic  of  the  epileptic  seizure  occurred. 
This  incision  at  once  arrested  the  convulsive  seizure,  because  it  interrupted 
the  paths  of  propagation  of  the  strong  currents  from  the  occipital  lobe  to  the 
sigmoid  gyrus. 

If  a  faradic  current  of  moderate  strength,  applied  to  the  precentral  con- 
volution of  a  monkey,  properly  prepared  and  anaesthetised,  provokes  distinct 
contractions  of  determined  groups  of  muscles  in  the  limbs,  and  if  the  electrode 
is  then  removed  to  a  point  in  front  of  the  motor  zone  of  the  limbs,  and  move- 
ments of  the  head,  eyes,  pupil  and  ear  are  then  induced  owing  to  stimulation 
of  the  respective  areas,  and  if,  again,  the  electrode  is  moved  to  another  point 
farther  forward  in  the  frontal  or  prefrontal  area  and  now  no  muscular  response 
is  obtained,  even  although  the  intensity  of  the  current  is  somewhat  increased, 
we  have  no  right  to  maintain  that  the  last-named  area  is  a  motor  centre.  If 
movements  are  provoked  only  by  greatly  increasing  the  strength  of  the 
current  or  by  prolonging  its  application,  we  are  not  in  a  position  to  draw 
legitimate  and  reliable  conclusions  from  the  experiment,  because  it  is  a  fact 
that  strong  electric  excitations  of  any  point  of  the  cortex  give  rise  to  con- 
vulsive seizures.  The  excitations,  either  by  contiguity  or  by  means  of  the 
direct  and  indirect  nervous  paths  of  communication,  reach  the  motor  zone, 
whence  eventuate  single  contractions  to  begin  with,  and  afterwards  an 
epileptiform  convulsion. 

After  a  lapse  of  many  years  we  find  Munk  *•  reappearing  on  the  scene 
with  renewed  ardour,  bringing  forward  fresh  arguments  in  support  of  his 
old  doctrine,  and  attacking  the  hypotheses  of  Ferrier,  Bianchi,  and  of 
Goltz.  He  attributes  the  intellectual  disturbances  observed  in  dogs  that 
have  suffered  mutilation  of  his  so-called  musculo-sensitive  zone,  partly  to  a 
rather  extensive  lesion  of  the  cerebral  cortex,  partly  to  shock,  and  partly 
also  to  subsequent  inflammatory  processes.  In  his  criticism  of  Flechsig's 
doctrine  he  stoutly  denies  the  existence  of  a  cortical  field  for  the  higher 
psychic  functions.  To  him,  the  cerebral  mantle  is  the  sphere  of  the  senses 
and  hence  an  aggregate  of  fields,  each  related  to  a  particular  sense.  Each 
sensory  sphere  is  an  organ  for  a  specific  perceptive  function,  for  representations 
and  for  sentiments  (Empfindungen) . 

Goltz  2  refuses  to  accept  the  involved  conception  of  Ferrier  and  of  Hitzig 
concerning  the  intellectual  function  of  the  frontal  lobes — i.e.  that  they  are 
the  seat  of  intelligence — and  expresses  views  similar  to  those  of  Munk, 
maintaining  that  the  whole  brain  is  the  organ  of  the  higher  psychic  functions. 

1  Munk.     "  t)ber  die  Ausdehnung  des  Sinnesphare  in  der  Grosshirnrinde."     Sitz. 
Berl.  d.  Preuss.  Akad.     1901. 

2  Goltz.     tJber  die  Verrichtungen  des  Orosshirns.     1881. 


THE  FRONTAL  LOBES  77 

He  maintains  that  it  is  not  possible  to  localise  in  any  particular  part  of  the 
brain  any  one  of  the  higher  manifestations  of  psychic  life  such  as  we  under- 
stand by  intelligence,  thought,  sentiment,  passion,  will.  He  insists  that 
every  part  of  the  cerebral  cortex  is  a  point  of  departure  for  those  higher 
manifestations.  Nevertheless,  in  dogs  which  had  both  frontal  lobes  muti- 
lated he  observed  certain  phenomena  similar  to  those  described  by  Bianchi 
in  his  first  communication,  such  as  clumsier  movements,  delayed  sensations 
and  changes  in  character  (one  of  Goltz'  dogs  bit  his  own  paw  when  excited). 
He  further  declares  that  after  extensive  and  deep  lesions  of  the  two  occipital 
lobes  there  is  also  loss  of  voluntary  energy.  This  he  inferred  from  the 
defective  resistance  exhibited  by  the  animals  to  passive  movements.1 

He  maintains  that  intelligence  has  no  relations  with  the  anterior  lobes 
of  the  brain  that  differ  from  the  relations  subsisting  between  it  and  any  other 
part  of  the  brain ;  that  the  disturbances  of  intelligence  which  follow  removal 
of  the  occipital  lobes  are  incomparably  graver  ;  and  that  Hitzig  and  Ferrier 
had  been  unable  to  free  themselves  from  the  old  prejudice  that  the  anterior 
lobes  of  the  brain  were  the  organ  of  intelligence.  He  writes  as  follows : — 
"  I  look  upon  the  demonstration  that  the  cortex  of  the  brain  is  the  organ  of 
the  higher  psychic  functions — i.e.  the  organ  of  intelligence,  in  all  its  parts — 
as  the  most  important  result  of  my  researches.  By  intelligence  I  mean  the 
faculty  of  elaborating  the  perceptions  of  the  senses  by  aid  of  reflection, 
with  a  view  to  action  suited  to  attain  a  definite  object.  I  am  not  sure  if 
philosophers  will  be  satisfied  with  this  definition.  It  is  sufficient  for  the 
physiologist." 

Moolman 2  and  Goltz  3  observed  two  facts  which  the  writer  was  able 
afterwards  to  confirm  : — 

(a)  Lesions  confined  to  the  frontal  lobes  are  followed  by  consequences 
that  are  less  significant  than  those  due  to  lesions  of  other  parts  of 
the  brain. 

(6)  Lesions  limited  to  one  frontal  lobe  produce  no  appreciable  effect. 

It  is  to  be  noted,  however,  that  there  is  a  great  divergence  between  this 
finding  and  the  assertion  of  Goltz  to  the  effect  that  extirpation  of  both  frontal 
lobes  gives  rise  to  disturbances  similar  to  those  which  follow  upon  removal 
of  the  parietal  lobes. 

Goltz  had  certainly  not  failed  to  observe  the  symptomatic  complex,  at 
least  in  its  more  obvious  details,  which  one  generally  finds  after  removal 
of  the  frontal  lobes,  such  as  general  excitability,  absence  of  control  over 
movements,  and  the  incoercibility  of  certain  reflexes,  in  dogs.  These 
symptoms,  however,  were  always  complicated  by  disturbances  of  general 
sensibility  and  of  certain  movements  because,  as  a  rule,  the  posterior  limit 
of  the  lesion  fell  upon  the  sigmoid  gyrus  or  even  on  a  point  behind  this.  On 

'Goltz.  "Zur  Physiologie  der  Grosshirns."  Arch  f.  Psychiatric,  xv.  1884; 
Pfluger's  Archiv.  1884.  Bd.  34;  Id.  Bd.  42. 

2  Moolman.     Researches  carried  out  in  the  laboratory  of  Goltz. 

3  Goltz.     Loc.  cit. 


78  THE  MECHANISM  OF  THE  BKAIN 

the  other  hand,  it  is  to  be  remembered  that  these  phenomena  were  judged 
in  the  light  of  a  doctrine  which,  for  a  long  time,  even  up  to  the  present  day, 
had  obtained  possession  of  the  minds  of  many  physiologists,  the  doctrine 
of  arrest  or  inhibition.  If  a  dog  has  its  frontal  lobes  removed  and  after- 
wards performs  marked  circus  movements,  running  in  a  mad  fashion  round  a 
very  wide  circle — a  symptom  observed  not  only  by  Goltz  but  also  by  Poli- 
manti  and  the  author — the  conclusion  is  that  there  is  a  defect  in  the  power 
of  arrest  or  inhibition,  as  the  result  of  which  the  animal  obeys  an  internal 
impulse — one  might  almost  say  a  mechanical  impulse — which  in  itself  is 
irresistible.  Goltz  even  went  further.  In  his  opinion  the  sensory  and 
motor  paralyses  which  followed  removal  of  the  frontal  lobes  were  not  the 
direct  effects  of  the  lesion  of  the  cerebral  centres  of  motion  and  sensation, 
but  indirect  effects,  in  this  respect  that  the  lesion  produced  a  transitory 
state  of  arrest  of  the  motor  centres  at  various  lower  levels  in  the  subcortical 
organs. 

Loeb  1  denies  the  psychic  functions  attributed  by  others  to  the  frontal 
lobes.  Admittedly  he  is  right  when  he  asserts  that  cerebral  lesions,  if  of 
slight  extent,  do  not  produce  psychic  disturbances,  because  they  do  not 
affect  the  associative  memory  (another  definition,  perhaps  unnecessary,  but 
useful) — and  that  it  is  only  extensive  bilateral  lesions  that  cause  more  or 
less  conspicuous  disorders  of  the  associative  memory.2  This  distinguished 
physiologist,  however,  was  unfortunate  both  in  his  observations  and  in  his 
conclusions,  if,  in  his  experience  of  a  number  of  cases  of  mutilation  of  both 
frontal  lobes  of  dogs,  he  never  noticed  any  difference  in  mental  behaviour 
between  sound,  healthy  dogs,  and  those  operated  upon. 

Luciani  3  is  one  of  the  physiologists  who  have  offered  very  strong  opposi- 
tion to  the  author's  views  concerning  the  function  of  the  frontal  lobes.  In 
the  last  edition  of  his  classic  work  *  he  strongly  supports  the  doctrine  of 
Flechsig.  He  admits  that  the  associative  centres  fulfil  higher  psychic 
functions,  but  does  not  ascribe  to  the  frontal  lobes  any  such  higher  functions, 
founding  his  argument  upon  the  brief  and  transitory  character  of  the 
symptoms  observed  in  animals  deprived  of  their  frontal  lobes.  He  writes 
as  follows  : — "  Neither  from  Munk's  experiments  nor  my  own,  nor  from 
those  of  Horsley  and  Schafer,  does  it  appear  that,  after  destruction  of  the 
prefrontal  lobes,  dogs  or  apes  differ  in  any  appreciable  way  from  intact 
animals,  so  far  as  intelligence  is  concerned."  He  attributes  the  changes  of 
character,  observed  by  Goltz  in  animals  which  had  suffered  mutilation  of  the 
fore-brain,  mostly  to  elimination  of  the  sensory-motor  zone,  and  to  a  slight 

1Loeb.  "Beitrage  zur  Physiologie  des  Grosshirns."  Pflilger's  Arch. 
Bd.  xxxix.  1886. 

2  Loeb.     Loc.  cit. 

3  Luciani.     Trattato  di  Fisiologia.     1912.     Vol.  iii. 

*  The  author  puts  aside  the  harsh  and  not  altogether  courteous  judgment  ex- 
pressed by  Professor  Luciani  in  the  first  edition  of  his  book,  because  in  a  renewed 
friendship  the  author  maintains  a  sincere  regard  for  his  work  as  a  physiologist  of 
very  high  standing. 


THE  FRONTAL  LOBES  79 

extent  to  destruction  of  the  prefrontal  area.  "  No  one,"  he  writes,  "  who 
has  been  long  occupied  with  the  effects  of  partial  destruction  of  the  brain 
in  dogs  or  monkeys,  can  fail  to  note  the  insignificance  and  brief  duration  of 
the  symptoms  presented  by  animals  after  removal  of  the  prefrontal  lobes." 
It  is  worthy  of  note  that  whilst  Professor  Luciani  does  not  attach  much 
importance  to  the  monkey  shown  by  the  author  at  the  International  Congress 
in  Rome,  in  1894,  he  assigns  a  greater  value  to  the  monkey  presented  by 
Sciamanna,  whose  conclusions  are  invalidated  by  the  result  of  the  post- 
mortem examination,  which  revealed  only  an  insignificant  loss  of  brain 
substance,  as  indeed  was  to  be  anticipated  from  the  statement  made  by 
Sciamanna  himself,  when  he  described  the  process  he  had  followed  in  his 
experiments.  The  technique  employed  in  his  excision  of  the  frontal  pole 
was  inadequate.  The  frontal  pole  is  but  a  small  portion  of  the  prefrontal 
lobe  and  a  still  smaller  part  of  the  frontal  lobe,  taking  into  account  the 
whole  extent  of  the  latter,  up  to  the  limits  assigned  to  it  in  front  of  the 
pre-Rolandic  convolution. 

Luciani  attaches  much  more  importance  to  the  parietal  area  so  far  as  the 
psychic  powers  are  concerned,  and  in  this  respect  agrees  with  Flechsig, 
although  he  bases  his  argument  upon  different  grounds.  He  states  that 
removal  of  the  parietal  area  (parieto- occipital  and  parieto- temporal)  does 
much  greater  damage  to  the  intelligence  of  dogs.  In  the  dog,  each  sensory 
sphere  not  only  has  its  own  particular  territory  but  also  possesses  an  area 
in  common  with  those  around  it,  an  area  which  constitutes  what  he  calls  a 
zone  of  interlocking  or  overlapping  of  the  various  sensory  regions  (visual, 
auditory,  olfactory,  somsesthetic) .  Owing  to  this  overlapping  we  get  the 
marginal  zones  (Flechsig)  of  the  various  sensory  areas  confused  as  one  area — 
the  parietal  lobe — regarded  by  Luciani  as  the  most  important  region  of  the 
dog's  hemisphere,  as  the  centre  of  centres  on  which  the  normal  association  of 
percepts  and  their  memory  images  depend.  This  conception  has  its  founda- 
tion in  the  fact  that  the  sensory  areas  are  not  neatly  and  precisely  delimited, 
•from  the  experimental  and  clinical  points  of  view.  They  are  certainly  not 
well  defined  in  man,  although  they  have  attained  a  much  greater  differentia- 
tion than  in  the  dog,  and  still  less  in  the  dog,  which  is  the  animal  preferred 
in  these  experiments.  One  must  always  bear  in  mind  the  fact  that,  in  the 
dog,  the  frontal  lobes  are  but  slightly  evolved,  whilst  temporo-parietal  lesions 
do  damage  to  the  mnemonic  perceptive  field  of  sight  and  hearing,  perhaps 
also  of  touch,  in  its  full  functional  efficiency. 

Luciani  points  to  the  results  of  the  researches  of  Kalischer,1  Horsley  and 
Schafer,  in  support  of  his  views. 

It  remains  to  be  shown  that  experimental  removal  of  the  parietal  zone 
of  Luciani  does  not  give  rise  to  disturbance  of  the  perceptive  process  in  any 
sensory  field.  A  dangerous  ambiguity  is  perpetuated  in  believing  or  in 
making  believe  that  those  who  ascribe  higher  intellectual  functions  to  the 
frontal  lobes  regard  the  cortical  fields  of  the  different  sensibilities  as  not 

1  Kalischer.  "  Berichte  Kgl.  Preuss.  Akad.  d.  Wissenschaf."  Berlin,  1907. 
Arch.  Anat.  u.  Physiol.  1909. 


80  THE  MECHANISM  OF  THE  BRAIN 

possessing  functions  of  a  psychic  nature.  If  we  lay  it  down  as  a  fundamental 
truth  that  the  sensory  spheres  are  organs  which  compose  and  conserve  the 
images  which  are  the  material  necessary  for  the  higher  mental  constructions, 
we  can  understand  that  when  the  temporal  or  parietal  or  occipital  lobes  on 
both  sides  are  removed,  the  mental  capacity  must  be  diminished  to  the  extent 
to  which  these  areas,  with  their  sensory  content,  contribute  to  the  working 
and  development  of  the  psychic  processes.  The  consequent  degradation, 
to  a  greater  or  less  extent,  of  the  entire  mental  capacity  of  the  animal  experi- 
mented upon  is  surely  very  obvious.  There  are  good  reasons  why  we  should 
accept  this  view,  all  the  more  when  we  remember  that  in  dogs  the  frontal  lobe 
has  not  assumed  control  of  the  mental  life,  which  revolves  mostly  in  the 
sensory  cortex.  In  the  relations  between  the  frontal  lobe  and  the  cerebral 
mantle,  when  the  former  is  still  in  process  of  development,  as  in  the  case  of 
dogs,  we  have  a  repetition  of  what  we  previously  found  in  the  relations  sub- 
sisting between  the  cerebral  cortex  and  the  optic  lobes  in  fishes,  and  even  in 
batrachians,  when  the  mantle  is  in  its  first  stage  of  evolution.  The  same 
argument  applies  in  the  case  of  man,  as  the  casualty  wards  of  our  hospitals 
show. 

We,  for  our  part,  hold  that  the  mental  defect  that  follows  removal  of  the 
frontal  lobes  affects  all  psychic  manifestations  in  the  case  of  the  dog  or  of 
the  monkey,  notwithstanding  the  fact  that  the  senses  and  their  respective 
sensory  areas  are  all  normal  and  fulfil  their  functions  in  a  regular  manner, 
and,  in  the  case  of  man,  notwithstanding  the  fact  that  the  areas  of  spoken 
and  written  language  likewise  remain  normal  and  functionate  regularly. 

The  terms  of  this  problem  cannot  be  altered.  We  still  await  a  reply 
to  the  question  :  "What  is  the  function  of  that  large  inexci table  mass  of 
brain  situated  in  front  of  the  motor  zone  ?  " 

According  to  Wundt l  the  frontal  lobes  are  the  centre  of  apperception. 
Like  most  modern  psychologists,  he  distinguishes  what  one  might  call  a 
sensory  perception — the  noticing  or  simple  perception  of  some  object  which 
excites  our  senses — and  an  attentive  perception. 

External  stimuli,  in  order  to  furnish  mental  elements  of  judgment,  must 
be  perceived  with  the  aid  and  intervention  of  the  attentive  faculty.  The 
perceptions  must  be  arrested  in  the  field  of  consciousness,  and  recognised. 
Attentive  recognition  is  what  Wundt  calls  apperception.  It  is  easy  to 
understand  that  recognition  can  only  happen  when  similar,  dissimilar,  or 
analogous  images  are  reawakened,  when,  as  James  would  say,  they  are  called 
up  into  the  associative  fields,  or,  as  the  writer  would  put  it,  recalled  from 
their  respective  perceptive  fields. 

It  is  evident,  however,  that  to  assign  the  faculty  of  apperception  to  the 
frontal  lobes  is  much  the  same  thing  as  ascribing  to  them  the  capacity  for 
recalling  from  the  sensory  centres  those  images  conserved  therein  and 
necessary  for  recognition,  so  that  in  this  sense,  although  Wundt  does  not 
say  so,  the  frontal  lobe  becomes  an  evocative  centre — i.e.  a  centre  regulating 
1  Wundt.  Grundzuge  der  physiolog.  Psychologie.  Bel.  1. 


THE  FRONTAL  LOBES  81 

the  mnemonic  function  of  all  the  sensory  centres.     Flechsig  appears,  recently, 
to  have  accepted  this  view,  as  we  shall  afterwards  see. 

Meynert l  expressed  the  opinion  that  Hitzig's  hypothesis  exceeded  the 
limits  of  physiological  induction,  and  only  served  in  a  provisional  way  to  fill 
a  blank  in  our  knowledge.  In  other  words,  it  lacked  a  scientific  foundation. 
On  the  other  hand,  Meynert  believed  that  there  was  some  ground  for  the 
view  put  forward  by  Munk,  because  he  thought  the  upright  posture  of  the 
body,  the  human  gait  with  trunk  erect,  the  manual  labour  of  man  (since  his 
upper  limbs  are  no  longer  employed  in  walking)  would  explain  the  existence 
of  a  large  cortical  motor  area  such  as  the  frontal  lobe,  provided  with  a  great 
mass  of  bundles  of  white  substance  which  would  constitute  the  anatomical 
substratum  of  the  mental  processes  of  the  respective  associations.  This 
view  is,  of  course,  contradicted  by  the  fact  that  the  extensive  prefrontal 
zone  is  not  excitable,  whereas  all  the  muscles  of  the  body  are  represented  in 
the  motor  area,  much  behind  the  field  of  these  experimental  mutilations 
which,  as  a  matter  of  fact,  do  not  give  rise  to  any  paralysis. 

Flechsig' s  ideas  regarding  the  function  of  the  frontal  lobe  are  neither 
clear  nor  yet  precise.  He  starts  out  with  the  fundamental  notion  that  an 
associative  zone  is  first  and  foremost  an  area  to  which  are  transmitted  and 
in  which  are  associated  the  products  of  the  surrounding  areas  of  sensibility. 
As  the  anterior  associative  zone  (frontal  lobe)  is  found  between  the  tactile 
area  (centre  of  sensibility  of  the  organic  ego)  and  the  olfactory  area,  he  infers 
from  this  that  its  function  is,  at  least  in  part,  that  of  transmitting  the  memory- 
traces  of  corporal  (somatic)  phenomena,  so  that  this  centre  would  play  a 
predominant  part  in  the  formation  of  the  ego,  in  so  far  as  it  is  composed  of 
feelings  and  voluntary  acts  and  mnemonic  traces  of  these.  Nevertheless, 
he  supposes  that  the  sphere  of  activity  of  the  frontal  lobe  is  not  confined 
to  this  function  alone.  He  does  not  express  any  opinion  as  to  whether  or 
not  its  functions  are  essentially  different  from  those  of  the  great  posterior 
centre  of  association.  The  function  which  this  centre  would  have,  in  common 
with  the  other  associative  centres,  would  be  that  of  combining  various  internal 
and  external  percepts,  as  well  as  calling  up  and  combining  their  memory- 
traces.  From  this  point  of  view  the  centres  of  association  dominate  the 
intellectual  life  and  are  the  true  organs  of  thought. 

That  Flechsig  attributes  a  very  high  intellectual  value  to  those  centres 
can  be  inferred  from  the  position  he  takes  up,  unsupported  though  it  be  by 
much  clinical  and  experimental  proof,  when  he  asserts  that  the  sensory 
image-records  can  only  be  reproduced  by  bringing  into  action  the  centres 
of  association,  without  allowing  for  the  intervention  of  the  centres  of  sensi- 
bility. In  the  first  chapter  we  have  seen  that  all  the  clinical  data  in  our 
possession  are  at  variance  with  this  mode  of  conceiving  the  centres  of  sensi- 
bility and  centres  of  association.  The  sensory  aphasic,  e.g.,  has  no  longer 
the  memory  of  words  though  he  certainly  has  that  of  objects.  He  perceives, 
1  Meynert.  Wanders,  d.  Sudwest  d.  N enrol  u.  Innerdrzte  in  Baden.  1883. 
F 


82  THE  MECHANISM  OF  THE  BRAIN 

imagines,  desires  and  recognises  objects  with  sight,  touch,  etc.,  but  does  not 
name  them,  because  the  centre,  where  are  formed  and  conserved  the  phonetic 
images  of  the  words  expressing  the  respective  objects,  is  destroyed.  He  has 
conserved  the  tactile,  visual  and  auditory  images  of  these  objects  and  makes 
use  of  these  as  he  did  before  he  became  aphasic.  He  remembers  and  recog- 
nises the  places  towards  which  he  directs  his  footsteps.  If  his  thought 
is  interdicted,  it  is  because  he  lacks  nouns  and  verbs  and  the  relative 
grammatical  inflexions. 

In  this  case  the  images  of  things  themselves  are  capable  of  being  recalled 
in  a  regular  manner.  When,  however,  there  is  an  injury  to  the  occipital 
lobes,  the  patient  speaks,  forming  phrases  and  sentences,  although  he  cannot 
reproduce  the  visual  images  of  objects  and  places  seen.  Even  here  we 
are  faced  with  a  mental  disorder,  inasmuch  as  the  conceptions  are  more 
difficult  and  imperfect,  because  the  visual  images,  which  are  such  a  large 
part  of  the  mental  content  and  so  necessary  for  recalling  the  respective 
words,  are  wanting. 

Clinical  observation,  unbiassed  and  unprejudiced,  goes  to  prove  that  the 
various  special  functions  of  sensibility  and  motility  have  their  origin  in 
different  cortical  areas,  which  are  functionally  and  anatomically  co-ordinated 
with  one  another.  Flechsig  ascribes  the  most  important  role  in  the  develop- 
ment and  display  of  the  higher  mental  processes  to  the  posterior  associative 
zone,  and  he  goes  on  to  say  that  the  height  of  the  forehead  depends  on  the 
volume  of  the  sensory  sphere,  and  this  in  its  turn  on  the  volume  of  the  body. 
The  height  of  the  forehead  is,  in  his  opinion,  not  a  direct  index  to  mental 
power.1  He  embraces  a  part  of  Munk's  idea  and  puts  forward  the  hypothesis 
that  the  frontal  lobe  is  the  greater  kina3sthetic  centre.  He  speaks  of  the 
Kdrperfiihlsphare  (body-feeling  sphere)  as  the  organ  to  which  come  the  nerve 
fibres  from  the  lower  centres  of  circulation,  respiration,  hunger,  thirst, 
well-being,  etc.  Critically  examined,  however,  this  statement  appears  rather 
arbitrary  and  improbable.  Monkeys  that  have  suffered  mutilation  of  the 
frontal  lobes  behave,  up  to  a  point,  like  healthy  monkeys.  Not  only  do  they 
move  about  and  perform  movements  with  a  definite  object,  measuring 
distances  and  taking  hold  of  things,  but  they  also  run  after  food  stuffs  and 
satisfy  their  appetite  in  a  normal  manner.  Their  chief  instincts  are  pre- 
served (hunger,  thirst,  sexual  instinct).  There  is  no  experimental  proof  to 
show  that  the  frontal  lobes  are  a  kinsesthetic  centre  and  accordingly  a  centre 
of  somatic  consciousness  (the  organic  ego,  which  is  the  nucleus  of  the 
personality) . 

The  frontal  lobe  certainly  plays  a  part  in  the  formation  of  the  ego  in  so 
far  as  it  contributes,  as  we  shall  see,  to  the  development  of  consciousness. 
This  does  not  mean  to  say  that  the  organic  ego  is  formed  in  the  frontal  lobe, 
because  all  our  experience  goes  to  show  that  the  cortical  area,  excitation  of 
which  modifies  the  organic  functions,  is  that  of  the  Rolandic  convolutions. 
A  few  experiments  with  electric  excitation  of  the  frontal  lobes,  which  seem 

1  Flechsig.  Geliirn  und  Seele.  Leipzig,  189G ;  Die  Localisation  der  geistigen 
Vorgange  insbesondere  der  Sinnesempfindungen  des  Menschen.  Leipzig,  1896. 


THE  FRONTAL  LOBES  83 

to  have  furnished  proofs  to  the  contrary,  are  open  to  considerable  doubt 
and  criticism,  as  will  be  seen  when  discussing  the  hypothesis  put  forward 
by  Sciamanna. 

Elechsig's  view  has  been  gradually  modified.  Briefly  put  it  is  as 
follows : — 

"  Granted  that  in  lesions  of  Broca's  area  we  have  to  deal  essentially  with 
particular  disturbances  of  memory,  this  special  form  of  amnesia  concerns 
the  frontal  lobe  in  particular."  These  phenomena  "  are  directly  related  to 
those  internal  phenomena  which  Wundt  has  grouped  under  the  term  apper- 
ception. I  therefore  speak  of  the  frontal  lobe  simply  as  a  centre  of  apper- 
ception." Since  the  apperceptive  process  is  essentially  one  of  evocation, 
and  as  he  admits,  a  connection  between  the  frontal  lobes  and  the  visual, 
auditory,  etc.  spheres,  the  frontal  lobe  thus  becomes  also  a  centre  of  attention 
and  an  evocative  agent.  On  the  other  hand,  the  union  of  the  nucleus  of  the 
somatic  consciousness  with  the  fields  of  the  external  impressions  would  be, 
as  a  whole,  an  exclusive  function  of  the  pre-frontal  lobe,  "  and  in  this,"  he 
continues,  "  I  find  myself  in  full  agreement  with  distinguished  Italian 
investigators  such  as  Bianchi,  Sergi,  Tamburini."  By  a  process  of  inter- 
pretation, which  it  is  needless  to  give  in  detail,  he  finds  the  bridge,  "  in 
Bianchi' s  demonstration  of  the  relations  of  the  frontal  lobe  with  sociability 
and  the  social  sentiments."  He  is  induced  to  admit  that  "the  most  im- 
portant factors  of  will  are  connected  with  the  frontal  associative  centres," 
although,  he  adds,  "  it  would  be  going  beyond  experimental  facts  did  we 
seek  to  locate  the  seat  of  voluntary  activity  and  of  attention  exclusively  in 
the  frontal  lobe." 

An  attempt  will  be  made  to  clear  up  this  point  in  a  succeeding  chapter. 
Meanwhile,  it  is  comforting  to  note  the  fact  that  such  an  acute  and  persistent 
investigator  as  Elechsig  is  coming  into  line  with  the  conclusions  which  the 
author  deduced  from  his  first  experiments. 

Sciamanna  2  set  out  to  inquire  whether  there  was  any  region  of  the  brain 
the  integrity  of  which  was  necessary  and  sufficient  for  the  fulfilment  of  the 
more  strictly  intellectual  functions.  This  is  an  erroneous  way  of  putting 
the  question  and  serves  only  to  perpetuate  ambiguity.  It  is  further  com- 
plicated by  Sciamanna' s  hypothesis  that  in  the  frontal  lobe  "  there  reside 
centres  of  projection  which  are  conjoined  with  the  bulbar  centres  of  organic 
innervation  by  means  of  ascending  and  descending  paths."  This  hypo- 
thesis merely  repeats  Flechsig's  first  assertion  in  another  form,  all  the  more 
since,  according  to  Sciamanna,  emotional  states  would  exercise  a  great 
influence  over  the  associative  dynamics,  and,  having  regard  to  the  organic 
basis  of  the  emotions,  one  could  thus  understand  the  importance  of  the 
pre-frontal  lobe  in  conscious  and  voluntary  attention.3 

1  Flechsig.     "  Hirnphysiologie  und  Willenstheorie."     Atti  del  Congresso  Intern, 
di  Psicologia.     1905. 

2  Sciamanna.     "  Le  funzioni  della  corteccia  cerebrale,"  ecc.     Clinica  Moderna. 
Anno  3a,  1897. 

3  Proceedings  of  the  International  Congress  of  Psychology.     Rome,  1905. 


84  THE  MECHANISM  OF  THE  BRAIN 

The  most  reliable  experimental  findings  do  not  bear  out  the  truth  of 
Sciamanna's  hypothesis  any  more  than  that  of  Flechsig. 

In  the  attempt  to  assign  a  large  measure  of  importance  to  the  frontal  lobe 
in  the  mechanism  of  the  emotions,  Sciamanna  transgresses  the  limits  of 
well-founded  experimental  facts.  Indeed,  Luciani l  states  that  stimulation 
of  any  point  of  the  motor  zone  excites  the  organic  phenomena  of  emotion, 
if  a  weak  or  moderate  current  is  employed.  Mislawski  and  Munk  obtained 
arrest  in  the  inspiratory  phase  by  exciting  a  point  of  the  frontal  lobe  in  front 
of  the  motor  zone.  W.  G.  Spencer,  Langelaan  and  Beyermann  obtained 
similar  results.  The  two  last-mentioned  investigators  denned  an  area,  in 
the  dog,  situated  at  the  extremity  of  the  sigmoid  gyrus  where  the  coronary 
meets  the  presylvian  fissure,  excitation  of  which,  with  a  weak  current,  pro- 
duced respiratory  acceleration  followed  by  inspiratory  arrest.2  The  observa- 
tions of  Bochefontaine,  Franyois-Franck  and  Pitres,  of  Bechterew  and 
Mislawski,  of  Sherrington,  of  Mosso  and  Pellacane,  who  have  demonstrated 
vesical  reactions  following  excitation  of  the  motor  zone,  and  those  of 
Pfungen  who  provoked  intestinal  movements,  do  not  bear  out  the  truth  of 
Sciamanna's  conclusions.  All  these  investigators  have  provoked  the  organic 
phenomena  of  emotions  by  exciting  the  sigmoid  gyrus  in  animals  or  the  bases 
of  the  superior  and  middle  frontal  convolutions  in  man  (Langelaan  and 
Beyermann) .  These  phenomena  are  not  elicited  by  exciting  the  pre-frontal 
lobe,  provided  strong  currents  are  not  employed. 

It  is  true  that  some  emotions  reinforce  the  associative  powers,  but 
these  are  the  higher  emotions,  the  sentiments,  not  the  primary  and  inferior 
emotions. 

If  the  terms  used  by  Sciamanna  are  to  be  interpreted  in  the  sense  of 
interest,  to  which  Smith  and  others  ascribe  great  importance  in  the  deter- 
minism of  human  conduct,  one  might  agree  to  accept  the  hypothesis  men- 
tioned. As  we  shall  see  hereafter,  interest  depends  on  the  individual  manner 
of  feeling  and  on  the  sum  and  colouring  of  the  ideas  representing  an  object 
to  be  attained  or  a  danger  to  be  avoided.  We  know  that  ideas  contain  a 
mnemonic  residuum  of  the  emotions  accompanying  the  sensations  which 
originally  went  to  form  the  content  and  essence  of  mind.  Nevertheless,  it 
is  necessary  to  draw  a  distinction  between  interests  of  an  inferior  order 
(arising  from  organic  desires,  appetites,  and  pressing  instincts  ;  those,  in  fact, 
most  closely  associated  with  the  organic  phenomena  of  the  primary  emotions) 
and  social,  moral,  political,  religious,  economic  and  scientific  interests, 
with  which  are  bound  up  an  infinite  series  of  intellectual  syntheses  and 
relative  resonances  in  the  consciousness. 

Sciamanna  reproduces  the  author's  view  but  expresses  the  opinion  that 
clinical  experience  has  not  confirmed  it,  or  at  least  has  not  given  constant 
results.  He  writes  as  follows  : — "  In  1900  Bianchi  stated  his  views  thus  : 
'  The  frontal  lobes  serve  for  the  conscious  fusion  of  the  two  great  activities 

1  Luciani.     Loc.  cit. 

2  W.  Langelaan  and  H.  Beyermann.     "  On  the  Localisation  of  a  Respiratory  and 
a  Cardio -motor  Centre  in  the  Cortex  of  the  Frontal  Lobe."     Brain,  1903. 


THE  FRONTAL  LOBES  85 

of  the  mind,  the  somatic -emotive  and  the  intellectual,  and  are  thus  the  organ 
of  physiological  connection  of  all  the  sensory  and  motor  products  of  the  other 
regions  of  the  cortex.  In  disease  of  the  frontal  lobes  the  capacity  for  opera- 
tions of  intelligence  of  the  higher  order  is  lost,  although  the  sensory  functions 
themselves  remain  uninjured.'  Having  regard  to  the  fact  that  clinical 
experience  has  not  categorically  demonstrated  my  assumption,  and  admitting 
that  '  explicit  experimental  proof '  is  also  lacking,  one  may  none  the  less 
hold,  on  the  basis  of  the  inductive  criteria  above  mentioned,  that  even  if 
the  frontal  lobe  by  its  influence  on  feeling  can  exert  in  man,  more  than  in 
animals,  an  indirect  influence  over  the  mental  manifestations,  intelligence 
must  nevertheless  be  the  result  of  the  work  of  the  entire  brain." 

From  a  practical  point  of  view  Sciamanna's  experiments  are  of  little 
value  when  it  is  considered  that  the  portions  removed  from  the  frontal 
cortex  of  his  monkeys  were  quite  insignificant :  0-99  gramme  from  one  lobe, 
1-29  grammes  from  another,  and  a  maximum  of  2-73  grammes,  which  re- 
present a  very  small  fraction  of  the  weight  of  the  vault  of  the  frontal  lobe 
of  either  side  in  a  small  monkey.  In  point  of  fact,  it  was  shown  at  the 
autopsy  that  the  frontal  lobe  had  been,  in  the  main,  preserved. 

The  same  criterion  should  be  applied  to  clinical  experience.  Only  ex- 
tensive bilateral  destructions  (and  more  particularly  destruction  of  the  left  lobe] 
produce  considerable  and  appreciable  modifications  of  intelligence  and  character. 

It  is  dangerous  to  draw  anatomical  and  physiological  conclusions  from 
imperfect  observations  such  as  those  of  Langelaan,  with  the  intention  of 
locating  the  seat  of  any  function  in  a  particular  part  of  the  cerebral  cortex. 
To  maintain  that  the  frontal  lobe  plays  a  part  in  the  essence  and  mechanism 
of  the  emotions,  as  an  organ  which  receives  kinaesthetic  images  which  would 
come  into  the  field  of  conscious  attention  and  thus  exert  an  influence  over 
the  associative  dynamics,  is  a  bold  hypothesis  in  which  there  is  a  good  deal 
of  mere  conjecture  and  certainly  no  basis  of  proof. 

The  view  that  the  frontal  lobes  are  essentially  an  inhibitory  organ  has 
been  put  forward  and  maintained  by  eminent  Italian  physiologists.  Indeed, 
it  should  be  mentioned  that  the  results  of  the  author's  investigations  and 
the  conclusions  which  he  considered  he  was  justified  in  drawing  from  them, 
met  with  very  strong  opposition  in  Italy. 

Libertini1  stated  the  problem  in  accurate  terms  and  attacked  it  with 
rigorous  methods  which  afforded  fairly  definite  results.  He  found  shortening 
of  the  time  of  the  tendonous  reflexes  after  mutilation  of  the  frontal  lobes 
more  in  the  anterior  than  in  the  posterior  limb  of  the  opposite  side.  This 
was  more  pronounced  after  extirpation  of  the  left  than  after  that  of  the  right 
frontal  lobe. 

The  notion  that  this  shortening  of  the  time  of  the  reflexes  was  due  to  loss 
of  the  inhibitory  function  of  the  frontal  lobes  was  rather  contradicted  by 

1  Libertini.  "  Sulla  tocalizzazione  dei  poteri  inibitori  nella  corteccia  cerebrale. 
Ricerche  speri  men  tali."  Arch,  per  le  Scienze  mediche.  Vol.  xix. ;  e  Arch.  ItaL  de 
Biologle. 


86  THE  MECHANISM  OF  THE  BRAIN 

the  investigations  of  Fano.1  This  investigator  excited  the  frontal  lobe  with 
electricity  for  five  seconds  and  at  the  same  time  provoked  a  reflex  by  f aradic 
excitation  of  the  skin.  He  found  that  whilst  the  time  of  reaction  was  notably 
lengthened  in  the  opposite  anterior  limb  it  was  shortened  in  that  of  the  same 
side,  the  myographic  curve  being  at  the  same  time  lowered. 

Oddi 2  confirmed  this  finding  by  another  method.  He  excited  the  fifth 
lumbar  motor  root  with  a  faradic  current,  a  metronome  being  interposed  in 
the  circuit,  and  produced  rhythmical  contractions  of  the  gastrocnemius 
which  were  registered  on  a  revolving  drum.  With  another  induced  current, 
he  then  excited  the  pre-frontal  lobe  (previously  laid  bare)  on  the  opposite 
side,  and  found  that  the  myographic  curve  underwent  a  significant  lowering. 
As  the  result  of  these  experiments,  Oddi  denied  that  the  frontal  lobes 
possessed  any  activity  of  high  psychic  value.  He  stoutly  maintained  that 
they  were  centres  of  inhibition  and  also  indicated  the  paths  by  which  this 
inhibit! ve  activity  influenced  the  spinal  medulla. 

Polimanti  3  arrived  at  pretty  much  the  same  conclusions.  As  the  result 
of  a  series  of  experiments  upon  dogs  he  concludes  that  the  most  striking 
phenomenon  following  upon  removal  of  a  frontal  lobe  is  the  circus- motion 
of  the  animal  towards  the  side  of  the  injured  hemisphere.  These  circus- 
movements  are  in  a  small  circle  during  the  first  few  days  after  the  operation, 
and  take  in  a  large  circle  after  several  weeks.  Both  types  of  movement 
last  only  a  certain  time,  then  disappear.  The  longer  or  shorter  duration 
depends  on  the  extent  of  lesion  ;  the  more  extensive  the  lesion,  the  longer 
the  duration  of  the  symptom,  more  especially  when  the  lesion  involves  the 
"  boundary-zones  of  the  frontal  lobe  "  (i.e.  the  sigmoid  gyms). 

Given  the  irresistible  character  of  these  circus- movements,  Polimanti 
(who,  a  priori,  favoured  the  doctrine  of  the  inhibitory  function  of  the  frontal 
lobe)  accounts  for  them  by  the  absence,  to  a  greater  or  less  extent,  of  restrain- 
ing influence  on  the  part  of  the  boundary- zones.  This  eminent  physiologist 
attributes  to  the  frontal  lobe  what  is  essentially  the  function  of  motor  innerva- 
tion  of  the  muscles  of  the  nape  of  the  neck,  the  head,  and  trunk  of  the  opposite 
side  (in  this  supporting  the  doctrine  of  Munk).  He  infers  from  his  experi- 
ments that  the  loss  of  function  of  the  frontal  lobe  destroyed  is  compensated 
by  the  surrounding  areas  when  (as  is  generally  the  case)  the  circus- movements 
disappear,  some  days  after  the  operation.  This  functional  compensation  he 
attributes  to  the  substance  bordering  zone  la  (frontal  lobe)  of  the  corre- 
sponding hemisphere  and  to  the  analogous  area  in  the  opposite  hemisphere, 
a  point  in  which  he  seems  to  agree  with  the  views  previously  advanced  by 
the  author  in  regard  to  functional  compensation.4 

Leaving  aside  the  question  of  compensation,  it  is  worth  while  examining 
this  author's  views  in  some  detail.  He  prefers  to  use  the  word  restraint. 

1  Fano.     Arch.  Italiennes  de  Biologic.     1895. 

2  Oddi.     Atti  della  Reale  Accademia  dei  Lincei.     Roma,  1895. 

8  Polimanti.  Contribute  alia  fisiologia  ed  alVanatomia  dei  lobi  frontali.  Rome, 
1906. 

4  Bianchi.     "  Le  compensazioni  funzionali."     La  Psichiatria.     1883. 


THE  FRONTAL  LOBES  87 

After  removal  of  the  frontal  lobes  "  there  is  wanting,  at  least  during  the  first 
few  days,  that  restraint  which  we  must  ascribe  to  zone  la  (frontal  lobe)  and 
the  parts  bordering  it." 

It  is  a  fact,  however,  that  more  intense  and  more  prolonged  circus- 
movements  are  always  observed  in  dogs  when  a  part  of  the  sigmoid  gyrus 
adjoining  zone  la  is  destroyed,  and  this  area  is  the  most  conspicuous  part 
of  the  Fiihlsphare  of  Munk  and,  in  the  dog,  is  both  motor  and  sensory. 

If,  then,  very  limited  lesions  of  zone  la  in  the  dog  give  rise  to  circus- 
movements  of  brief  duration,  if  these  movements  are  more  marked  and 
lasting  when  the  lesion  extends  backwards  to  the  sigmoid  gyrus,  and  if,  again, 
the  same  symptoms  are  obtained  when  we  spare  the  frontal  lobe  and  limit 
the  experimental  lesion  to  the  sigmoid  gyrus  alone  (not  to  mention  other 
regions  of  the  brain,  injury  of  which  gives  rise  to  similar  circus -movements), 
we  have  no  right,  strictly  speaking,  to  infer  therefrom  that  zone  la  is  the 
centre  of  inhibition  of  the  movements  of  the  head  and  trunk.  It  is  well  to 
bear  in  mind  that  one  cannot  judge  the  function  of  a  given  cerebral  region 
from  the  symptoms  that  present  themselves  immediately  after  an  experi- 
mental lesion,  because  these  symptoms  include  the  effect  of  circulatory  and 
functional  disturbances  of  neighbouring,  and  sometimes  also  of  distant 
parts  which  have  functional  and  perhaps  also  anatomical  relations  with  the 
area  destroyed  in  the  experiment.  One  should  not,  it  is  true,  exaggerate 
the  significance  of  the  phenomena  of  diaschisis,  upon  which  Monakow  lays 
a  good  deal  of  stress.  At  the  same  time,  one  must  accept  it  as  a  funda- 
mental rule  that  the  investigator  who  seeks  to  determine  the  function  of 
separate  parts  of  the  brain,  by  means  of  experimental  lesions,  must  not 
judge  the  function  of  the  part  destroyed  from  the  symptoms  that  appear 
immediately.  He  must  wait  for  days,  and  often  weeks,  before  he  can  arrive 
at  a  just  appreciation  of  the  permanent  functional  deficit,  at  the  same  time 
taking  into  account  functional  compensations  and  substitutions. 

Polimanti  draws  attention  to  two  other  phenomena  :  (a)  ataxia  on  the 
side  opposite  to  the  lesion  ;  (6)  exaggeration  of  the  deep  reflexes. 

1.  The  ataxia  on  the  opposite  side  is  more  evident  in  the  anterior  than 
in  the  posterior  limb  and  it  disappears  first  in  those  cases  in  which  the  lesion 
has  been  limited  or  incomplete. 

In  another  place  we  will  deal  with  frontal  ataxia  associated  with  tumours 
of  the  frontal  lobe  in  man,  but  here  it  is  to  be  mentioned  that,  in  the  dog, 
the  form  of  ataxia  to  which  Polimanti  draws  attention  is  precisely  that 
observed  after  destructive  lesions  of  the  sigmoid  gyrus.  This  symptom,  which 
the  author  has  frequently  observed,1  was  also  insisted  upon  by  SchifT,2  who 
held  that  the  ataxic  symptoms  presented  by  dogs  after  removal  of  the 
sigmoid  gyrus  were  due  to  sensory  disturbances,  and  resembled  the  ataxia 
produced  after  section  of  the  posterior  columns  of  the  spinal  cord. 

1  Bianchi.     Sui  centri  motori  corticali.     Communication  to  the   Association  of 
Naturalists  and  Physicians.     Naples,  1878. 

2  SchifT.     "  Dei  pretesi   centri    motori    negli  emisferi  cerebrali."     Riv.  Sper.  di 
Fren.      1895. 


88  THE  MECHANISM  OF  THE  BRAIN 

2.  Exaggeration  of  the  knee- j  erks  is  a  symptom  that  is  constantly  associated 
with  a  lesion  of  the  motor  area  or  pyramidal  paths  or  parts  surrounding  the 
motor  area.  It  is,  indeed,  one  of  the  fundamental  rules  in  the  semeiology 
of  cerebral  affections  that  lesions  situated  in  the  neighbourhood  of  the  motor 
zone  or  in  the  pyramidal  paths  give  rise  to  exaggeration  of  the  deep  reflexes. 

We  also  know  that,  apart  from  destructive  lesions,  any  irritative  process 
in  the  motor  cortex  causes  exaggeration  of  the  deep  reflexes.*  What  is  the 
use,  then,  of  labouring  the  question  of  "  a  real  and  actual  restraint  ...  or 
a  pronounced  inhibitory  effect  "  in  the  frontal  lobe  of  the  dog  ? 

The  simple  fact,  which  Polimanti  does  not  dwell  upon,  is  that  after 
extirpation  of  both  frontal  lobes,  dogs  perform  movements  which  have  the 
appearance  of  irresistibility  inasmuch  as  they  are  in  constant  motion  or 
very  nearly  so,  the  pauses  being  of  very  brief  duration.  We  will  see  after- 
wards what  is  the  psychological  significance  to  be  given  to  this  symptom, 
already  observed  by  Goltz,  and  described  and  interpreted  by  the  author  in 
Brain,  1895.  Whether,  as  Polimanti  thinks,  the  frontal  lobe  exercises  a 
regulating  and  reinforcing  action  upon  the  movements  of  the  limbs  of  the 
opposite  side,  like  that  ascribed  to  the  cerebellum,  save  for  a  difference  in 
degree,  is  a  point  that  is  very  doubtful,  as  is  also  the  question  whether  or 
not  this  influence  is  exercised  through  the  paths  that  are  supposed  to  exist 
between  the  frontal  lobes  and  the  cerebellum,  the  so-called  fronto-ponto- 
cerebellar  tract,  which  Polimanti  failed  to  find  in  the  dog.  From  his  experi- 
ments upon  monkeys  he  concludes  that,  in  these  animals,  the  frontal  lobes 
"  have  no  outstanding  influence  upon  mentality,  such  as  would  warrant  us 
in  regarding  them  as  the  seat  of  the  higher  psychic  manifestations." 
"  To  speak  to-day,"  he  continues,  "  of  particular  centres  and  organs  pre- 
siding over  intelligence  as  we  speak  of  motor  and  visual  centres,  etc.,  is  a 
very  risky  thing  and  would  only  be  taking  us  back  to  the  views  of  years 
long  past." 

Ivory  Shepherd  l  expresses  a  very  different  view.  He  is  one  of  the  few 
investigators  who  took  such  precautions  as  would  enable  him  to  detect  altera- 
tions in  the  mental  manifestations  of  cats  and  monkeys  resulting  from 
mutilation  of  the  frontal  lobes.  In  his  investigations  he  followed  the  methods 
adopted  by  Thorndike.2  The  animals  to  be  experimented  upon  were  trained 
to  acquire  new  associations,  and  their  mental  capacity  was  then  re-  examined 
after  mutilation  of  the  frontal  lobes.  The  same  plan  had  already  been 
followed  by  Hitzig  and  the  author,  but  Shepherd's  method  was  much  more 
ingenious.  After  extirpation  of  the  frontal  lobes,  cats  were  found  to  have 
lost  the  memory  of  what  they  had  learned  with  regard  to  the  food  box, 
although,  to  an  observer  unacquainted  with  all  the  details,  the  cats  seemed 
to  be  quite  normal.  In  point  of  fact,  some  of  the  cats  had  lost  their  recent 

*  Because  the  pyramidal  fibres  originate  in  the  deeper  cell -layers. 

1  Shepherd.     "  On  the  Functions  of  the  Cerebrum."     The  Frontal  Lobes.     1907. 

2  Thorndike.    Animal  Intelligence  and  Food  Boxes,  and  an  article  by  this  author 
in  The  American  Journal  of  Physiology.     August  1902, 


THE  FRONTAL  LOBES  89 

acquisitions  (experimental),  whilst  their  impulses,  habits  and  inherited 
tendencies  were  preserved,  as  were  also  their  emotional  reactions. 

So  far  as  emotions  are  concerned,  Shepherd  made  a  special  study  of  these 
in  the  monkeys  and  cats  upon  which  he  operated  and  found  that  they  under- 
went no  noteworthy  alteration,  although  he  observed  a  greater  domesticity 
and  friendliness  in  some  of  the  animals. 

Whether  sentimentality  and  emotivity  are  or  are  not  modified  by  re- 
moval of  the  frontal  lobes  is  an  open  question.  Shepherd  carried  out  certain 
experiments  with  the  express  purpose  of  settling  this  point  and  he  declares 
that  the  emotional  reactions  after  removal  of  the  frontal  lobes  remained  the 
same  as  they  were  prior  to  the  operation.  Many  of  his  cats  showed  the  same 
familiarity  as  before  the  operation  and  were  displeased  when  treated  harshly. 
In  monkeys,  no  difference  was  observed  in  the  emotional  responses.  This 
keen  and  unprejudiced  observer,  however,  does  not  hesitate  to  place  before 
us  certain  doubtful  points.  "We  cannot  distinguish,"  he  says,  "between 
emotion,  properly  speaking,  and  emotional  reaction,  and  it  is  consequently 
difficult,  indeed  impossible,  to  say  that  the  emotions  were  not  altered.  We 
are  only  justified  in  concluding  that  the  reaction  remained  the  same  ;  the 
emotions  may  or  may  not  have  been  different. " 

It  should  be  mentioned  that  separation  of  the  frontal  lobe  was  incomplete. 
In  most  cases  it  remained  in  relation  with  the  brain  behind,  and  it  is  not  to 
be  wondered  at  if  the  resultant  changes  in  the  affective  reactions  of  the 
animals  operated  upon  were  slight.  Nevertheless,  from  the  sum-total  of 
numerous  experiments,  to  which  further  allusion  will  be  made  in  a  subsequent 
chapter,  he  arrived  at  conclusions  which  almost  entirely  confirmed  the 
results  of  the  writer's  previous  experiments,  amongst  them  the  following  : — 

(a)  When  the  frontal  lobes  are  destroyed  recent  acquisitions  are  lost. 
(6)  The  loss  of  associations  does  not  result  from  lesions  of  other  parts 
of  the  brain. 

(c)  The  loss  of  associations  is  not  due  to  shock. 

It  seems  that,  in  cats,  mutilation  of  the  frontal  lobes  may  have  some 
influence  upon  the  organic  metabolism,  although  he  did  not  observe  this  in 
monkeys.  Here  it  may  be  remarked  that  Ferrier  found  a  marked  alteration 
of  nutrition  in  monkeys,  after  lesions  of  the  occipital  lobes  but  observed  no 
appreciable  difference  after  extirpation  of  the  frontal  lobes. 

Roncoroni1  attempted  to  arrive  at  a  judgment  as  to  the  function  of  the 
frontal  lobes  by  examination  of  the  intimate  structure  of  the  frontal  cortex. 
In  the  writer's  opinion,  however,  any  conclusion  as  to  the  functions  of  the 
frontal  lobe  that  is  based  on  histological  investigation  is  premature.  When 
we  remember  that  the  myelogenetic  geography  of  Flechsig  does  not  agree 
with  that  of  other  investigators  and  that  remarkable  differences  exist  between 
the  results  obtained  by  Brodmann,  Vogt,  Campbell,  and  Bolton,  and  that 

1  Roncoroni.  "  Le  funzion  dei  lobi  prefontali,"  etc.  Rivista  di  Patologia 
nervosa  e  mentale.  1911. 


90  THE  MECHANISM  OF  THE  BRAIN 

a  good  deal  depends  upon  the  exact  methods  employed,  upon  the  strict 
details  of  technique,  and  on  the  chemical  state  of  the  brain,  it  will  be  realised 
that  we  cannot  found  a  doctrine  upon  cytotecture.  Investigations  in  this 
direction  are  not  calculated  to  throw  light  upon  the  question  of  the  function 
of  the  frontal  lobe. 

Roncoroni  is  opposed  to  those  who  locate  the  higher  mental  activities 
in  the  frontal  lobes.  "We  cannot  admit,"  he  writes,  "  that  the  more  highly 
evolved  faculties  have  any  limited  seat,  nor  can  we  accept  as  admissible 
those  theories  which  localise  intelligence,  memory,  will  or  consciousness  in 
the  frontal  lobes." 

This  distinguished  neurologist  of  the  University  of  Parma  makes  use  of 
the  old  notion,  renewed  by  Monakow  under  the  term  diaschisis,  that  as  the 
frontal  lobe  takes  part  in  the  associative  overlapping  with  many  or  all  of 
the  other  parts  of  the  brain,  a  lesion  of  the  frontal  lobes  disturbs  the  function 
of  the  whole  brain.  "  If  it  is  true,"  he  writes,  "  that  higher  intelligence 
and  emotivity  require  for  their  full  development  the  integrity  of  all  the 
psychic  organs,  it  is  clear  that  these  will  be  generically  altered  by  lesions  of 
the  frontal  lobes  just  as  they  would  by  injury  to  any  other  part  of  the  cortex." 
The  frontal  lobes,  he  thinks,  are  composed  of  several  different  cytotectural 
fields,  fulfilling  elementary  functions  which  represent  phases  in  the  psychic 
reflex  arc,  the  structure  of  which  does  not  correspond  either  with  that  of  the 
motor  fields  or  with  that  of  the  sensory  areas.  "  These,"  he  writes,  "  have 
to  do  with  the  elementary  functions  of  that  part  of  the  psychic  reflex  arc 
corresponding  to  the  associations  which  manifest  themselves  on  the  threshold 
of  the  conscious  act,  in  the  pre-emissive  period  of  the  psychic  reflex  arc." 

Roncoroni  is  not  at  all  clear  on  this  point.  What,  indeed,  would  be  the 
elementary  functions  of  that  part  of  the  psychic  reflex  arc  ?  The  associa- 
tions, it  seems  ;  and  associations  of  what  ?  Of  images,  memories,  experiences, 
emotions  and  actions  !  Now,  the  frontal  lobes  must  either  form  these  or 
evoke  them — i.e.  recall  them  from  their  respective  areas.  If  this  is  his 
view,  we  can  claim  to  be  in  agreement,  to  a  certain  extent,  but  agreement 
is  impossible  with  the  preconception  of  diaschisis,  and  this  again  is 
irreconcilable  with  the  conception  of  elementary  functions  as  applied  to  the 
frontal  lobes. 

If  lesions  of  the  frontal  lobe  disturb  the  psychic  life,  this,  according  to 
Roncoroni,  is  due  to  the  fact  that  higher  intelligence  and  emotivity  (these 
high  functions)  require  for  their  full  development  the  integrity  of  all  the 
psychic  organs,  "  so  that  these  functions  would  be  altered  in  a  generic  fashion 
by  lesions  of  the  frontal  lobes  just  as  they  would  by  injury  to  any  other  part 
of  the  cortex,"  for  the  simple  reason  that  the  prefrontal  lobe,  like  any  other 
part  of  the  cortex,  is  a  collection  of  fields  and  areas.  From  this  point  of  view 
the  frontal  lobes  become  deprived  of  their  great  dignity.  They  are  regarded 
as  possessing  no  special  function,  and  as  merely  providing  an  additional 
number  of  psychic  fields  and  elementary  functions,  like  any  other  part  of  the 
cerebral  cortex.  In  its  origin  this  conception  has  a  physical  basis.  Suppose 
for  a  moment  that  intelligence  emanates  from  the  cortical  fields  (arcs)  like 


THE  FRONTAL  LOBES  91 

electricity  from  electric  batteries  ;  it  becomes  more  intense  and  reaches  a 
higher  potential  as  the  number  of  areas  increases,  just  as  the  intensity  of 
the  electric  current,  ceteris  paribus,  increases  with  an  increased  number  of 
batteries.  It  is  difficult,  however,  to  understand  what  Roncoroni  means 
when  he  says  that  the  frontal  psychic  arcs  are  precisely  those  which  manifest 
themselves  on  the  threshold  of  the  conscious  act  in  the  pre- emissive  period.  It 
is  a  pity  that  Italians  should  adopt  the  involved  form  of  language  employed 
by  some  Germans  who  aim  at  originality.  Unless  we  are  mistaken,  however, 
his  "  threshold  of  the  conscious  act  in  the  pre- emissive  period  "  would  be  the 
moment  of  deliberation  in  the  volitional  act  which,  again,  is  based  on  evoca- 
tion and  association  of  the  memories  of  the  experience  of  life  that  are  the 
patrimony  of  the  personality,  comprising  the  knowledge  of  social  obligations 
and  the  social  sentiment,  in  which  may  be  summed  up  \hefiat  of  deliberation. 
Now,  if  destruction  of  other  parts  of  the  brain  gives  rise,  as  we  know  it  does, 
to  quite  another  kind  of  deficit,  then  the  functioning  of  the  brain  is  not  to  be 
likened  to  that  of  a  group  of  electric  batteries,  or  even  an  orchestra,  for  in 
the  latter  case  the  addition  of  new  instruments  serves  to  raise  the  musical 
art  into  the  sphere  of  the  highest  and  most  wonderful  harmonies. 

We  can  agree  with  Lugaro,1  who  partly  accepts  Flechsig's  notion  and 
puts  forward,  in  another  form,  the  view  we  have  held  for  many  years — viz. 
that  the  frontal  lobes  are  the  organ  which  "  registers  the  story  of  the  acts 
of  all  one's  life  (experience),  the  organ  which  feels  the  most  intimate 
impulses  of  the  organism,  and  elaborates  the  particular  individual  mode  of 
reaction  to  external  stimuli."  Lesions  of  the  frontal  lobe  do  damage  to  the 
personality  and  alter  the  individual  character.  That  is  the  constant  finding. 
Not  only  animals  operated  upon  but  also  many  men  who  suffer  from  extensive 
lesions  of  the  frontal  lobes  exhibit  a  profound  alteration  of  character.  The 
actions  of  those  who  have  suffered  damage  to  the  frontal  lobes  are  impulsive 
in  character,  whilst  the  actions  of  healthy,  well- developed  men  are  deliberate 
and  based  on  experience  which,  again,  is  bound  up  with  representations  and 
imaginations.  The  historical  experience  of  the  ego  is  the  result  of  repre- 
sentations of  the  modifications  undergone  under  the  influence  of  stimuli,  in 
the  first  place,  and  then  of  actions  performed  and  the  consequences  of  these. 
If  we  are  not  mistaken,  this  representative  power  is  based  on  evocation,  in 
which  case  the  actions  are  always  the  result  of  the  impulse  of  the  ego,  accord- 
ing to  its  constitution,  and  also  of  the  inhibition  of  impulses,  which  is  generated 
by  representations.  Mental  life  in  all  its  manifestations  is  the  product  of 
collaboration,  in  synthesis,  of  the  representative  and  emotional  contents  of 
the  personality,  a  point  which  we  shall  seek  to  make  clear  in  another  chapter. 

Monakow  2  joins  issue  with  those  who  hold  that  the  frontal  lobes  are 
organs  for  the  higher  mental  processes.     His  conclusion  is  based  on  the 

1  Lugcaro.     Atti  del  Congresso  della  Societa  di  Neurologia  in  Napoli.     April  1908. 

2  Monakow.     Gehirnpathologie,  1905,  e   Uber  der  gegenvcirtigen  Stand  der  Frage 
nacli  der  Localisation  in  Grosshirn.      1902. 


92  THE  MECHANISM  OF  THE  BRAIN 

assertion  that  it  is  not  the  case  that  the  development  of  the  frontal  lobe  is 
a  feature  characteristic  of  the  higher  mammals.  He  states  that  in  ungulates 
(horse,  ox,  goat)  the  frontal  lobes  form  no  less  than  30  per  cent,  of  the  entire 
volume  of  the  fore-brain,  whilst  the  white  substance  of  the  frontal  group  of 
convolutions  is  much  less  developed.  In  the  following  chapter  we  shall 
see  what  truth  there  is  in  this  statement. 

In  Monakow's  opinion  clinical  observations  do  not  furnish  material 
sufficient  to  prove  the  functional  role  of  the  frontal  lobes.  This  neurologist 
of  Zurich  admits  a  certain  agreement  between  some  of  the  results  obtained 
in  the  old  investigations  of  Goltz,  Ferrier,  Hitzig  and  Bianchi,  but  suggests 
that  the  operative  technique  did  not  fulfil  the  necessary  aseptic  requirements, 
and  that  it  is  consequently  necessary  to  take  into  account  secondary  in- 
flammatory processes  which  would  not  be  without  some  effect  upon  the 
mentality  of  the  monkeys  operated  upon.  In  support  of  his  view,  he  mentions 
the  results  of  the  latest  researches  of  Munk,1  Grossglick,2  and  Horsley  and 
Schafer,3  which  he  regards  as  positive,  in  the  sense  that  extirpation  of  both 
frontal  lobes  in  the  monkey  did  not  give  rise  to  any  essential  psychic  altera- 
tions, nor  did  it  affect  the  behaviour  of  the  animals  operated  upon.  Against 
the  conception  that  the  frontal,  lobes  are  exclusively  an  associative  centre 
in  the  sense  of  Flechsig,  he  brings  forward  anatomico-experimental  investiga- 
tions in  dogs  and  macaques  in  the  brains  of  which,  following  mutilation  of 
the  frontal  lobes,  there  was  found  undoubted  secondary  degeneration  of  the 
anterior  and  middle  nuclei  of  the  optic  thalamus  (Monakow  and  Rutishauser). 
This  would  prove  that  the  frontal  lobe  possesses,  at  least  in  those  animals, 
projection  bundles  which  bring  it  into  direct  relation  with  subcortical  ganglia. 

Rossolimo  (reported  by  Bechterew  4)  found  sensory  and  motor  disturb- 
ances as  well  as  alteration  of  the  psychic  functions  in  dogs  which  had  suffered 
mutilation  of  both  frontal  lobes.  The  former  consisted  in  a  weakening  of  the 
musculature  and  a  kind  of  ataxia  of  the  movements,  the  latter  in  a  variety 
of  psychic  excitability,  dysorientation,  general  diminution  of  the  reflexes, 
enfeeblement  of  intellect,  and  marked  lowering  of  the  power  of  judgment. 

Bechterew 5  maintains  that  all  questions  regarding  the  localisation  of 
the  higher  psychic  functions  can  only  be  settled  on  the  basis  of  experience 
and  clinical  observation.  After  a  critical  review  of  Flechsig's  doctrine  and 
a  clear  exposition  of  the  author's  researches  and  deductions  regarding  the 
function  of  the  frontal  lobes,  he  arrives  at  conclusions  in  perfect  agreement 
with  the  results  of  the  author's  old  and  recent  investigations. 

1  Munk.     "  Ausdehn.  d.  Sinnes.  in  der  Grosshirnrinde."     Sitzberichten  d.  Akad. 
d.     Wissensch,    1899,    1900,    1901;     Id.    "Folgen    des    Sensibilitatsverlustes    der 
Extremitaten  fur  deren  motilitat."     Sitz'ungsberichte  d.  Konig  Preus.  Akad.      1903. 

2  Grossglick.     "  Physiologie  der  Stirnlappen."     Archiv.  fur   Anat.  u.   PJiysiol. 
1895. 

3  Horsley    and    Schafer.     "  Functions    of    the    Cerebral    Cortex."     Philosoph. 
Transactions.     1888. 

4  Loc.  cit. 

5  Bechterew.     Die  Functionen  der  Nervencentra.     Heft  3.     Jena,  1911. 


THE  FRONTAL  LOBES  93 

The  alteration  in  character  observed  in  dogs  operated  upon  by  Bechterew 
and  by  Zulowski  in  Bechterew's  institute  was  very  pronounced.  At  the 
outset  the  animals  exhibited  a  condition  of  marked  psychic  arrest,  laziness, 
somnolence,  and  reactive  indifference  as  compared  with  what  they  exhibited 
prior  to  mutilation  of  the  frontal  lobes.  With  the  disappearance,  however, 
of  symptoms  observed  during  the  early  stage,  there  were  observed  other 
important  symptoms  related  to  the  psychic  field,  and  these  exhibited  the 
feature  of  persistence,  for  the  animals  were  kept  alive  for  one  or  two  months. 
Two  of  them  exhibited  a  high  degree  of  irascibility  and  all  showed  signs  of 
inaptitude,  a  lack  of  consideration,  fear,  amnesia,  and  incapacity  to  make 
use  of  previous  experiences.  Their  habits  and  methods  of  eating  were  also 
markedly  altered.  They  made  no  response  to  the  calls  of  the  attendant, 
and  they  hardly  reacted  to  caresses  or  to  threats.  When  caressed  they  mani- 
fested no  friendliness  ;  instead,  there  was  trembling  of  the  body  and  lowering 
of  the  tail.  As  a  rule  they  were  apathetic,  although  an  occasional  animal 
was  restless,  irritable  and  aggressive. 

During  the  week  following  the  operation,  sight,  hearing,  and  sometimes 
also  the  tactile  sense,  remained  normal.  The  animals  certainly  recognised 
objects  but  had  entirely  lost  that  higher  faculty  of  recognition  which  consists 
in  associating  the  actual  impression  with  that  of  past  experience,  and  of 
acting  in  accordance  therewith. 

This  higher  faculty  of  recognition  depends  to  a  great  extent  on  the  process 
known  in  subjective  psychology  as  judgment  and  consequential  conclusion,  a 
process  which  is  very  closely  connected  with  attention  and  choice  of  action 
and,  on  the  whole,  is  to  be  regarded  as  a  regulative  psychic  activity. 

Bechterew  has  long  been  recognised  as  an  investigator  and  psychologist 
of  undoubted  authority,  and  one  can  reasonably  assign  great  value  to  the 
results  of  these  researches  which  were  carried  out  in  an  unprejudiced  manner. 
His  experiments  were  very  rigorously  conducted  and  shed  new  light  on  the 
results  of  previous  inquiries  into  this  subject. 


CHAPTER  III 

Evolution,  Morphology,  and  Structure  of  the 
Frontal  Lobe 

THE  law  of  the  progressive  development  of  the  brain,  and  of  the  cortex  in 
particular,  is  confirmed  by  the  evolutionary  story  of  the  frontal  lobe. 

It  is  well  established  that  the  frontal  lobe  makes  its  appearance  very  late 
in  the  evolution  of  the  central  nervous  system.  No  trace  of  it  is  to  be  found 
in  the  lower  vertebrates  (fishes,  batrachians,  reptiles) .  In  these  the  anterior 
extremity  of  the  brain  is  represented  by  an  extension  of  the  hippocampic 
formation.  Moreover,  the  structure  of  the  cerebral  cortex,  when  it  first 
appears,  is  very  simple.  In  the  lower  fishes,  the  cerebral  hemisphere  is 


N.O 

Fig.  24 

O.  OLF.  Olfactory  lobe.— N.O.  Optic  nerve.— V.  Lateral  ventricle.— P.M.  Pallium 
membranosum.—  CE.  Cerebellum.— COR.  STR.  Corpus  striatum  (after  Jacob) 

represented  by  a  mere  membrane,  in  the  structure  of  which  there  is  as  yet 
no  true  nervous  substance  (pallium  membranosum).  Even  when  nervous 
structure  commences,  the  principal  part  of  the  hemisphere  consists  of  the 
corpus  striatum,  more  especially  the  caudate  nucleus  which,  phylogenetically, 
may  be  regarded  as  an  important  motor  organ,  because  it  receives  bundles 
of  fibres  from  the  olfactory  apparatus.  The  corpus  striatum,  which  is  highly 
developed  before  the  neopallium  assumes  its  functions,  receives  not  only 
olfactory  fibres  but  probably  .also  others  coming  from  the  visceral*  organs, 
and  transmits  nervous  waves  which  are  resolved  into  movements  of  loco- 
motion as  required  in  the  search  for  nourishment,  or  respiratory  movements, 
or  those  belonging  to  the  sexual  functions.  In  the  lower  fishes,  the 
membranous  pallium  encloses  a  space,  filled  with  lymph  (cerebro- spinal  fluid), 
which  is  the  lateral  ventricle,  and  the  surface  of  the  corpus  striatum  projects 
freely  into  this  cavity.  The  membrane  may  be  regarded  as  a  protective 
organ  (Fig.  24).  By  degrees  -it  becomes  replaced  by  the  cerebral  cortex. 
This  occurs  even  in  the  higher  fishes,  but  to  a  much  larger  extent  in  the 
higher  vertebrates.  Up  to  that  point  in  the  scale  of  fishes  where  the  pallium 

94 


STRUCTURE  OF  THE  FRONTAL  LOBE 


95 


membranosum  begins  to  acquire  a  nervous  structure,  the  corpus  striatum 
is  the  sole  organ  which  functions.  In  the  myxine  the  pallium  is  composed 
of  two  layers  of  cells  the  structure  of  which  is  mainly  hippocampic. 

In  amphibians  we  have  the  development  of  an  episphere.     The  dorsal 
portion  of  this  belongs  to  the  olfactory  sphere,  which  by  degrees  becomes 


Fig.  25. — Brain  of  amphibian  ;  sagittal  section 
(after    Edinger) 

circumscribed  within  the  hyposphere.  There  are,  however,  points  in  the 
cerebral  pallium  of  amphibians  (as  also,  in  that  of  the  myxine  and  the  petro- 
myzon,  though  less  numerous)  where  the  cellular  elements  have  no  relations 
with  the  olfactory  apparatus.  In  amphibians  and,  to  a  greater  extent,  in 
reptiles  the  cerebral  mantle  presents  specially  characteristic  features  in  the 
cell-structure.  The  nerve-cells  are  at  the  same  time  more  highly  developed. 
Figures  24,  25,  26,  represent  sagittal  sections  of  the  brains  of  a  lower 
fish,  an  amphibian  and  a  reptile,  and  show  clearly  that  in  these  vertebrates 


Fig.  26. — Brain  of  reptile  ;  sagittal  section 
(after  Edinger) 

the  fore-brain  becomes  gradually  thicker,  and  at  the  outset  seems,  as  it  were, 
a  prolongation  of  the  central  olfactory  apparatus. 

In  birds,  we  find  the  whole  mass  of  cortical  substance  much  more 
developed.  This  development  coincides  with  the  commencing  differentiation 
of  the  functions  of  the  cortex,  for  experiments  on  the  brain  of  the  pigeon 
demonstrate  the  existence  of  an  area,  in  the  anterior  and  upper  part  of  the 
hemisphere,  which  is  capable  of  being  excited  with  electricity. 

In  Figures  27,  28,  29,  one  can  observe,  at  a  glance,  the  progressive  develop- 
ment of  the  fore-brain  from  fishes  to  batrachians  and  from  these  to  birds, 
as  well  as  the  inverted  volumetric  relations  between  the  fore-brain  and  the 
optic  lobes. 


96 


THE  MECHANISM  OF  THE  BRAIN 


In  the  lower  mammals  we  find  an  excitable  area  already  distinctly 
differentiated  and  delimited.  This  is  the  motor  zone.  It  occupies  the 
anterior  and  external  part  of  the  hemisphere,  on  which  now  appears  the 
forerunner  of  the  crucial  sulcus.  In  rodents  this  is  located  well  forwards 
towards  the  anterior  extremity  of  the  hemisphere.  It  is  short  and  shallow 
and  is  surmounted  in  front  by  a  small  rudimentary  mass. 

Figure  30  represents  in  diagrammatic  fashion  the  brain  of  a  rabbit.  The 
area  within  the  circle  is  approximately  the  motor  zone,  according  to  Ferrier's 


c.t 


C.A 


-  C,E 


Fig.  27 
Brain  of  fish 


Fig.  28 
Brain  of  frog 


Fig.  29 
Brain  of  bird 


CA.  Fore-brain.— O.  Optic  lobes.— CE.  Cerebellum 


Fig  30.— Brain  of  rabbit 

SC.  Crucial  sulcus 
The  circle  represents  approximately  the  motor  area 

experiments.1  The  anterior  extremity  represents,  as  it  were,  an  evolutionary 
outgrowth  of  the  frontal  pole  of  the  pallium.  In  the  higher  mammals  this 
anterior  or  frontal  part  is  more  or  less  developed,  although  it  does  not  always 
bear  an  evident  relation  to  the  development  of  intelligence,  so  far  as  one 
can  judge  from  the  scanty  observations  hitherto  made.  For  example,  it  is 
comparatively  small  in  the  brain  of  the  rat,  which  manifests  intelligence, 
but  is  relatively  much  smaller  still  in  that  of  the  dolphin,  which  is  a  stupid 
animal,  although  in  it  the  parietal  lobe  has  attained  enormous  development 
(Fig-31).* 


1  Ferrier.     The  Functions  of  the  Brain.     1876. 

2  Vino.  Bianchi.     "  II  mantello  cerebrale  del  delfino.' 
delle  scienze  fisiche  e  chimiche  di  Napoli.     1905. 


Atti  della  R.  Accademia 


STRUCTURE  OF  THE  FRONTAL  LOBE  97 

It  is  only  in  the  higher  mammals  that  we  find  a  more  appreciable  develop- 
ment of  the  frontal  lobe.  In  these  as/  e.g.,  in  the  dog,  we  find  the  frontal 
extremity  of  the  hemisphere  not  only  more  developed  but  also  more  distinct 
from  the  sigmoid  gyras  owing  to  the  appearance  of  the  presylvian  sulcus. 

In  the  brain  of  the  dog,  the  hemispheric  mass  is  already  very  large,  the 
convolutions  are  more  distinct,  the  sulci  deeper  and  the  frontal  lobe  well 
outlined  (Fig.  32). 

Amongst  different  members  of  the  cat  family  (i&m.felidce)  the  frontal  lobe 

2    e  6    e       5 


\\\ 


r 


'6 

C 

3    ct 
Fig    31. — Brain  of  dolphin 

1.  Ectosylvian  fissure.— 2.  Suprasylvian  fissure.— 3.  Lateral  fissure.— 4.  Ectolateral  sulcus.— 
5.  Interhemispheric  fissure. — (>.  Crucial  sulcus. — e.  Anterior  division  of  sigmoid  gyrus. — 
e'.  Posterior  division  of  sigmoid  gyrus 

shows  considerable  differences  in  size.     In  the  ordinary  cat,  again,  it  is  much 
less  developed  than  in  the  dog.1 

Some  writers  hold  the  crucial  sulcus  to  be  the  analogue  of  the  fissure  of 
Rolando  and  the  two  branches  of  the  sigmoid  gyrus  to  represent  the  two 
central  convolutions  in  monkeys  and  in  man  (Munk,  Leuret) .  Others,  again, 
including  Broca,  Meynert,  Eberstaller,  regard  the  presylvian  fissure  (the 
vordere  Hauptfurcken  of  Pansch)  as  corresponding"  to  the  Rolandic  fissure 
in  man  and  in  monkeys.  In  the  former  case  the  frontal  lobe,  though  still 
fairly  small,  is  quite  appreciable  and  is  continuous  behind  and  above  with 
the  sigmoid  gyrus.  In  the  latter  case  one  should  have  to  regard  only  that 
part  of  the  mantle  lying  in  front  of  the  presylvian  fissure  as  pre-Rolandic, 
so  that  the  frontal  lobe  would  be  represented  by  a  very  small  portion  indeed. 

1  See  the  excellent  study  of  0.  Winkler  and  Ada  Potter.     An  Anatomical  Guide 
to  Experimental  Researches  on  the  Cat's  Brain.     Amsterdam,  1909. 
G 


98 


THE  MECHANISM  OF  THE  BKAIN 


Eberstaller l  declares  that  in  carnivorous  mammals  the  frontal  lobe  is  still 
very  small  if  not  rudimentary.  Now,  as  the  presylvian  fissure  is  placed  in 
front  of  and  not  above  the  sylvian  fissure  one  can  understand  how  the  frontal 
lobe  in  this  group  of  mammals  is  still  small  in  size,  as  compared  with  the 
parietal  lobe,  which  is  much  more  developed. 

Much  discussion  has  taken  place  apropos  of  the  development  of  the 
frontal  lobe  of  the  ox,  the  sheep  and  the  horse,  in  relation  to  the  intelligence 
of  these  animals. 

In  ruminants  the  frontal  lobe  would  appear  to  be  relatively  more  developed 
than  in  the  dog,  although,  from  what  we  know,  the  intelligence  of  the  sheep 


L.P 


sps 


Fig.  32.— Brain  of  the  dog 

(From  Ellenberger  and  Baum.     Anat.  descr.  du  Chien) 

LF.  Frontal  lobe.— SC.  Crucial  sulcus.— SPS.  Presylvian 
fissure. — CSA.  Anterior  sigmoid  or  pre-crticial  con- 
volution.— CSP.  Posterior  sigmoid  or  post-crucial 
convolution 

and  the  ox  is  much  inferior  to  that  of  the  dog,  leaving  aside  the  intelligence 
of  the  horse,  which  some  regard  as  still  sub  judice. 

Tenchini  and  Negrini 2  found  a  marked  analogy  between  the  cerebral 
cortex  of  man  and  that  of  the  horse  and  the  ox.  These  two  investigators 
regard  the  convolutions  of  the  frontal  lobes  as  organs  of  perfecting.  On 
the  other  hand,  the  study  of  mentality,  as  exhibited  by  the  ox,  the  sheep  and 
the  goat,  does  not  support  the  judgment  founded  on  anatomical  observation. 
How  is  it  that  these  organs  of  perfecting  should  give  such  poor  results  in 
ruminants,  which  would  appear  to  have  well- developed  frontal  lobes  ?  Either 
the  conclusion  is  unfounded  or  the  premises  are  wrong.  The  truth  is  that 
the  frontal  lobes  are  not  so  highly  developed  as  has  been  affirmed. 

It  is  of  the  utmost  importance  that  this  question  of  fact  should  be  cleared 
up,  all  the  more  since  Monakow  points  to  the  marked  development  of  the 
frontal  lobes  in  the  domestic  ruminants  and  to  the  notorious  stupidity  of 

1  Eberstaller.     "Das  Stirnhirn."     Ein  Beitrag  zur  Anatomie  der  Oberflache  des 
GrossMrns.     Leipzig,   1890.     One   may  profitably  compare  the  valuable  atlas  of 
Jakob. 

2  Tenchini    and   Negrini.     Sulla   corteccia   cerebrale    degli   equini    e   dei    bovini, 
studiata  nelle  sue  omologie  con  fjuella  delVuomo.     Parma,  1899, 


STRUCTURE  OF  THE  FRONTAL  LOBE  99 

these  animals  as  a  strong  argument  against  the  physio-psychological  dignity 
which  I  assign  to  these  lobes. 

With  this  object  in  view  I  have  examined  the  brains  of  oxen  and  of  sheep 
(Figs.  34,  35,  36,  37),  the  examination  being  conducted  on  the  lines  followed 
by  Zimmerl.1  My  results  have  been  so  confirmatory  of  the  findings  of  this 
investigator  that  I  venture  to  say  the  erroneous  notion  as  to  the  great 


LO 


Fig  33.— Brain  of  horse 

LO.  Olfactory  lobe.— 1.  Orbital  lobe.— 2.  Presylvian  fissure.— 
3.  Sigmoid  gyms,  anterior  branch. — 4.  Crucial  sulcus. — 
5.  Sagittal  pole.— 6.  Accessory  crucial  sulcus 

development  of  the  frontal  lobes  in  these  mammals  can  be  definitely  disposed 
of,  once  and  for  all. 

In  Figure  33  I  reproduce  from  Zimmerl's  work  the  figure  of  the  brain  of 
the  horse,  and  I  have  compared  it  with  the  brain  of  a  horse  which  I  secured 
for  this  study.  If  the  crucial  sulcus  should  correspond  to  that  marked  2 
in  the  figure  almost  nothing  would  be  left  of  the  frontal  lobe,  for  the  so-called 
orbital  lobe,  marked  1  in  the  figure,  would  have  to  be  regarded  as  a  part 
of  the  motor  area.  If  the  crucial  sulcus  corresponds  to  that  marked  4,  then, 

1  Zimmerl.     Trattato  di  anatomia  veterinaria.     Vol.  iii.  :  Sistema  nervoso. 


100 


THE  MECHANISM  OF  THE  BRAIN 


when  we  take  into  consideration  the  fact  that  in  the  dog  the  signioid  gyms 
extends  to  the  presylvian  fissure  and  that  it  is  more  than  probable  that  the 


Fig.  34. — Superior  surface,  brain  of  ox,  photographed  from  above 

and  in  front 
Es.    Ectosylvian    convolution. — sc.    Crucial    sulcus. — sp.     Presylvian    fissure 


Fig,  35. — Brain  of  ox,  external  surface 

ft.  Fissure  and  convolution  of  Sylvius.—  Es.  Ectosylvian  convolution.— ps.  Sagittal  pole.— 
s/.  Sylvio-frontal  sulcus 

same  thing  happens  in  the  horse,  which  has  an  enormously  developed  muscula- 
ture, the  frontal  lobe  still  remains  very  small,  as  compared  with  the  great 
development  of  the  occipito-parietal  mass  of  the  horse's  brain. 

The  same  thing  holds  good  with  regard  to  the  brain  of  the  ox. 

In  Figure  34,  which  is  the  photograph  of  the  brain  of  an  ox,  taken  from 


STRUCTURE  OF  THE  FRONTAL  LOBE  101 

the  front  and  close  at  hand,  the  crucial  sulcus  (sc)  is  situated  in  front  of  the 
sagittal  pole.  Now,  if  we  consider  the  extent  of  the  motor  area  surrounding 
the  crucial  sulcus,  we  will  be  convinced  that  what  remains  in  front  repre- 
senting the  frontal  lobe  or,  according  to  Zimmerl,  the  orbital  lobe,  is  a  very 
small  part  of  the  cerebral  mantle,  in  fact  only  a  portion  of  the  convolutions 
1  to  9  in  the  figure  taken  from  Zimmerl  (orbital  lobe  and  anterior  common 
convolution) .  It  is  further  to  be  observed  that  the  disposition  of  the  con- 
volutions of  the  cerebral  mantles  of  the  ox  and  sheep,  which  resemble  that 
of  the  horse  in  almost  every  respect,  is  quite  different  from  the  plan  of  archi- 
tecture in  the  brain  of  the  dog  or  the  monkey.  The  Sylvian  fissure  (S)  is 


Fig  36. — Intel-hemispheric  surface  of  the  brain  of  the  ox 

Note  the  anastomosis  of  the  convolution  of  the  corpus  callosum  with  the  median  surface  of  the 
sagittal  convolution  cs 

l>s.  Sagittal  pole. — sea.  Accessory  crucial  sulcus. — <js.  Posterior  branch  of  the  sigmoid  gyrus. — 
sc.  Crucial  sulcus.— s.  and  s.  Median  surfa.ce  of  orbital  lobule.— cs.  Accessory  calloso-orbital 
anastomosis 

almost  vertical  (Fig.  35)  and  is  found  in  front  of  a  line  dividing  the 
cerebral  hemisphere  into  two  equal  parts.  The  ectosylvian  convolution, 
Es,  is  large,  and  is  prolonged  backwards  as  well  as  forwards  where  it  is 
separated  from  the  anterior  common  convolution  (9,  in  Zimmerl's  figure) 
by  a  sulcus  which  I  would  call  Sylvio-frontal  (sf) .  The  frontal  lobe  would 
thus  consist  of  a  part  of  the  hemisphere  situated  in  front  of  the  presylvian 
sulcus  (a  part  of  the  orbital  lobe  1  and  a  part  of  the  anterior  common 
convolution  (9)). 

On  the  external  aspect,  the  crucial  sulcus  is  not  visible  in  Figure  35  but 
is  situated  in  front  of  the  sagittal  pole,  ps.  When  we  take  into  account 
the  extent  of  the  motor  area  in  front  of  ps,  the  development  of  the  frontal 
lobe  is  very  obviously  rudimentary.  One  has  to  bear  in  mind  that  the 
sagittal  convolution  is  separated  from  the  ectosylvian  convolution  by 
the  parietal  fissure  which  is  very  deep  and  prolonged  forwards  almost  to 
the  frontal  pole,  distinctly  separating  the  ectosylvian  convolution  from  the 
supposed  motor  area  and  from  the  orbital  lobule,  and  it  is  this  fact  that  has 


102  "  THE  'MECHANISM  OF  THE  BRAIN 

given  rise  to  considerable  doubt  as  to  the  extent  respectively  of  the  motor 
zone  and  of  the  frontal  lobe. 

On  the  anterior  part  of  the  median  or  interhemispheric  aspect  (Fig.  36) 
the  crucial  sulcus  is  marked  sc.  Behind  it  is  the  accessory  crucial  sulcus 
sea,  and  behind  that  the  sagittal  pole,  ps.  The  posterior  division  of  the 
sigmoid  gyrus  on  the  median  aspect  is  represented  by  gs.  What  remains 
in  front  of  the  sigmoid  gyrus  is  the  continuation  on  the  median  aspect  of  the 
region  marked  1  (Fig.  33)  on  the  external  surface  (orbital  lobule).  The 
convolution  of  the  corpus  callosum  cca  is  strongly  developed  in  ruminants 
and  anastomoses  to  a  variable  extent  (vide  cs)  with  the  orbital  convolutions 
of  which  only  a  portion,  in  my  opinion,  goes  to  form  the  frontal  lobe. 

In  any  case  the  frontal  lobe  would  be  represented  by  the  convolution 
which  is  the  prolongation,  to  the  pole,  of  the  sagittal  convolution  which,  on 


Fig.  37. — Brain  of  sheep,  median  aspect 

sea.  Accessory  crucial  sulcus. — sc.  Crucial  sulcus. — cca.  Callosal  con  volution. — 
cs.  Calloso-sagittal  anastomosis 

the  external  surface,  is  distinctly  separated  from  the  ectosylvian  convolution 
by  the  deep  parietal  fissure.  This  convolution,  curving  underneath,  becomes 
the  gyrus  rectus  and  forms  a  hollow  which  receives  the  large  olfactory  bulb. 
Everything  points  to  that  part  of  the  anterior  lobe  being  an  olfactory  organ, 
all  the  more  because  this  single  convolution,  along  with  the  large  olfactory 
bulb,  constitutes  the  base  of  orbital  surface  of  the  frontal  pole. 

On  the  median  aspect  of  the  brain  of  the  sheep,  as  shown  in  Figure  37, 
the  crucial  sulcus  sc  is  situated  well  forwards  ;  sea  is  the  accessory  crucial 
sulcus.  The  convolution  of  the  corpus  callosum  is  enormously  developed. 
It  is  divided  by  a  superficial  sulcus  into  two  portions,  the  upper  of  which 
anastomoses  with  the  sagittal  convolution  so  that  it  is  very  difficult  to  decide 
how  much  of  a  frontal  lobe  there  is  in  these  animals. 

I  had  hoped  to  carry  out  a  series  of  experiments  with  the  object  of  defin- 
ing the  limits  of  the  motor  area  in  the  sheep  by  means  of  electric  excitation, 
but  the  absence  of  the  hospital  staff  on  military  duty  since  1915  prevented 
this.  Still,  when  we  take  into  consideration  the  relatively  great  size  of  the 


STRUCTURE  OF  THE  FRONTAL  LOBE 


103 


callosal  convolution,  cca,  and  the  fact  that  the  sagittal  convolution  (which 
in  front  of  the  sulcus  sc  curves  underneath  to  become  the  orbital  lobule) 
assumes  considerable  relations  with  the  olfactory  lobe — a  fact  which  would 
lead  us  to  believe  that  it  is  there  mainly  a  hippocampic  cortical  organ — it 


AI 


A  A 


Fig.  38 

PS.  Sagittal  pole.— SC.  Crucial  sulcus.— AT.  Excitable  area  for 
muscles  of  neck  and  trunk. — AI.  The  same  for  hind  limb. — 
AA.  Fore  limb  with  less  marked  movements  of  posterior 
limb.— PA.  Opening  of  eyelids.— P.  Closing  of  eyelids.— 
O.  Movements  of  ear 


Fig.  39 

O.  Area  for  movements  of  ear.— P.  Closing  of  eyelids.— 
PA.  Opening  of  eyelids. — AA.  Movements  of  anterior 
limb  and  to  a  less  extent  of  the  posterior  limb.— 
AI.  Movements  of  posterior  limb  and  to  a  slight  extent 
also  the  anterior 

seems  clear  that  the  remaining  part,  which  we  can  rightly  regard  as  the 
frontal  lobe,  is  a  small  portion. 

Owing  to  the  difficulties  experienced  during  war-time  I  was  able  to  carry 
out  only  one  experimental  inquiry,  the  results  of  which,  however,  I  consider 
fairly  conclusive.  In  a  lamb  three  months'  old  I  laid  bare -a  large  area  of 
the  brain.  As  usual,  I  measured,  with  a  sledge,  the  minimum  faradic  current 
necessary  to  excite  movements  of  the  limbs  and  of  the  head,  and  with  small 
platinum-tipped  electrodes,  provided  with  a  hand  interrupter,  I  was  able 


104  THE  MECHANISM  OF  THE  BRAIN 

to   mark   out  with   certainty,   after  repeated  tests,  the  points   of   motor 
excitation  indicated  in  Figures  38  and  39. 

If  these  findings  are  correct  and  if  it  be  admitted  that  the  anterior  ex- 
tremity of  the  ectosylvian  convolution  has  no  part  in  common  with  the 
frontal  lobe,  the  disproportion  between  the  development  of  the  parieto- 
occipital  portion  and  that  of  the  part  that  can  be  assigned  to  the  frontal  lobe 
is  so  apparent  that  it  is  surprising  how  writers  of  authority  still  persist  in 
bringing  forward  the  weak  argument  that  there  is  remarkable  development 


CRR 


F.2 • 


Fig.  40. — Brain  of  orang-outang 

SR.  Fissure  of  Rolando.  —  CPR.  Pre-Rolandic  convolution.  —  FS.  Superior  frontal  con- 
volution.— F2.  Middle  frontal  convolution. — F3.  Third  or  inferior  frontal  convolution.— 
SPR.  Pre-frontal  sulcus 

of  the  frontal  lobes  in  the  ox  and  the  sheep  which  are  stupid  animals,  and 
that  the  parietal  lobes  are  those  which  show  a  development  more  parallel 
with  intelligence. 

In  monkeys  and  especially  in  apes  (primates)  the  development  of  the 
frontal  lobe  attains  a  high  degree.  The  brain  presents  the  same  architectural 
plan  as  in  the  human  being,  and  at  the  same  time  its  weight  is  much  greater 
relatively  to  the  weight  of  the  body.  Elementary  cerebral  functions  are 
better  localised,  and  the  functional  differentiation  more  pronounced,  so  that 
the  functional  areas  are  better  defined,  as  compared  with  those  in  the  cat 
and  the  dog,  and  correspond  more  closely  to  the  plan  of  functional  differentia- 
tion of  the  human  cerebral  cortex.  In  point  of  fact,  it  is  on  the  frontal  lobe 
of  the  monkey  alone  that  it  has  been  possible  to  arrive  at  a  precise  distinction 
of  areas  which  behave  differently  under  electric  stimulation,  or  present 
differences  in  histological  structure.  These  are,  as  we  shall  shortly  see,  the 
pre-Rolandic  convolution,  the  pre-central  intermediate  area,  the  frontal 
area  properly  so-called,  and  the  pre-frontal  zone. 


STRUCTURE  OF  THE  FRONTAL  LOBE  105 

It  is  well  at  this  point  to  make  reference  to  a  delicate  question  concerning 
the  morphology  of  the  frontal  lobe  in  monkeys.  Is  there  a  third  (inferior) 
frontal  convolution  in  apes  ?  This  is  an  important  question  because  it 
would  be  wrong  to  judge  a  priori  of  the  absence  of  an  organ  to  which,  in 
man,  many  ascribe  a  special  function,  simply  because  that  function  does 
not  exist  or  is  supposed  to  be  completely  absent  in  monkeys.  Marchand  l 
has  emphasised  this  point. 

Whatever  be  the  function  performed  by  the  third  frontal  convolution  in 
man,  be  it  or  be  it  not  the  motor  area  for  spoken  language,  it  represents,  in 
the  monkey,  an  evolutionary  phase  of  what  it  is  in  man.  The  fact  remains 
that  in  the  frontal  lobe  of  the  higher  monkeys  the  third  frontal  convolution 
does  exist.  Marchand  (Loc.  cit.)  singles  it  out  in  the  orang-outang.  Beevor 


C.P.R 


Fig.  41. — Brain  of  macacus 

(after  Jakob) 

S.  Fissure  of  Sylvius.— R.  Fissure  of  Rolando.— CPR.  Pre- 
Rolaudic  convolution.— SPR.  Pre-Rolandic  sulcus.— SP. 
Frontal  sulcus  which  separates  the  superior  from  the 
inferior  frontal  convolution 

and  Horsley  found  it  also  in  the  gorilla  and  the  chimpanzee.  In  the  two 
last  named  the  third  frontal  presents  the  same  features  as  in  the  human 
brain.  It  anastomoses  with  the  inferior  part  of  the  ascending  frontal  and 
with  the  second  frontal  convolution.  In  those  anthropoid  apes  the  inferior 
frontal  sulcus  is  clearly  present,  although  it  is  much  more  superficial  in  the 
brain  of  the  orang-outang  (Fig.  40)  than  in  that  of  the  others.  , 

The  fact  that  in  the  foot  of  the  third  frontal  convolution  the  layer  of  the 
large  pyramidal  cells  is  more  distinct  and  thicker  than  in  the*first  and  second 
frontal,  and  the  presence  of  a  greater  number  of  Betz  cells  (though  this  is 
denied  by  Brodmann)  would  support  the  doctrine  of  the  motor  function 
of  the  foot  of  the  third  frontal  convolution.  Its  structural  details  are  always 
Rolandic  in  nature,  like  those  of  the  intermediate  frontal  area  described  by 
Campbell  and  Turner. 

In  tracing  the  phylogenetic  development  of  the  brain  we  observe  a 
progressive  increase  of  the  frontal  lobe  which,  almost  throughout  the  scale, 
1  Marchand.  Die,  Morfoloyie  des  Stirnlappens,  etc.  Jena,  1893. 


106 


THE  MECHANISM  OF  THE  BRAIN 


maintains  a  certain  parallelism  with  the  growth  of  intelligence.     Even  in 
the  different  species  of  monkeys  we  find  a  gradual  development  of  the  frontal 


F.3 


Fig.  42. — Brain  of  one  of  the  cinocephalidaj  which  were  the 
subjects  of  experiment 

R.  Fissure  of  Rolando. — CPR.  Pre-Rolandic  convolution. — 
FS.  Superior  frontal  convolution.  — SF.  Superior  (1) 
frontal  sulcus.—  x.  Inferior  (?)  frontal  sulcus  more  marked 
here  than  in  the  illustration  taken  from  Jakob. — SPR. 
Pre-frontal  sulcus. — F3.  Embryo  of  the  third  frontal 
convolution,  or  orbital  operculum  of  the  frontal  lobe 


Fig.  43. — Brain  of  cinocephalus 
(Jakob) 

R.  Fissure  of  Rolando.— CPR.  Pre-Rolandic  convolution.— SF.  Frontal 
sulcus. — x.  Commencing  of  inferior  frontal  sulcus. — SPR.  Pre-frontal 
sulcus 

lobe,  from  the  macaques  to  the  cebidse,  then  to  the  anthropoid  apes,  and 
finally  to  man. 

The  brain  of  the  lower  cibus  (Fig.  41)  is  very  simple.  The  pre-frontal 
sulcus  is  situated  well  forwards,  the  pre-Rolandic  convolution  is  very  broad, 
there  is  no  trace  of  a  second  frontal  sulcus.  In  the  brain  of  the  higher  cibus 
we  find  a  conspicuous  number  of  small  sulci  on  all  the  convolutions,  including 


STRUCTURE  OF  THE  FRONTAL  LOBE  107 

those  of  the  frontal  lobe  (Figs.  42  and  43).  Altogether,  the  frontal  lobe 
has  attained  a  relatively  marked  development.  On  the  lower  frontal  con- 
volution there  appears  a  new  sulcus  which  assumes  different  forms  in  different 
members  of  the  same  family  (Figs.  42  and  43).  There  is  every  reason  to 
believe  that  this  is  the  forerunner  of  the  inferior  frontal  sulcus,  and  that  it  is 
significant  of  the  commencing  distinction  of  a  third  frontal  convolution, 
which  is  then  found  more  developed  in  the  orang-outang,  the  gorilla,  and  the 
chimpanzee. 

Taking  into  account  what  we  have  learned  of  the  crucial  sulcus  and  the 
architectural  plan  of  the  convolutions  related  to  it,  it  seems  a  very  suggestive 
hypothesis  that  the  development  of  the  frontal  region  of  the  human  brain 
has  proceeded  upon  lines  already  distinctly  laid  down  in  the  lower  apes.1 

The  superficial  extent  of  the  cerebral  mantle  in  the  middle-grade  monkey 
cebus),  in  the  orang-outang,  and  in  European  man,  respectively,  is  in  the 
proportion  1:5:17.  The  total  volume  of  cortex  is  as  1  :  5  :  24.  In  richness 
of  cells  the  ratio  is  1  :  8  in  the  cibus  and  orang-outang,  and  10  :  100  in  the 
orang-outang  and  man.2 

The  total  number  of  cells  in  the  cortex  of  the  orang-outang  is  one  thousand 
millions  as  compared  with  ten  thousand  millions  in  man.  The  entire  brain 
participates  in  this  enormous  development,  but'the  great  mass  of  the  frontal 
lobe  more  than  any  other  part.  As  a  matter  of  fact,  if  we  take  into  con- 
sideration the  entire  length  of  the  hemisphere  between  the  two  poles  of  the 
human  brain,  the  frontal  lobe  from  its  anterior  tip  to  the  centre  of  the  fissure 
of  Rolando  occupies  40  to  41  per  cent. ,  and  in  some  cases  even  more,  of  the 
length. 

There  is  no  lack  of  proof  which  controverts  the  statements  of  Flechsig 
and  Luciani.  If  we  trace  the  development  of  the  brain  in  mammals  it  is 
precisely  the  anterior  part  which  develops,  as  one  might  say,  ex  novo.  The 
frontal  lobe  of  lower  mammals — e.g.  the  dolphin — contains  a  smaller  number 
of  cells,  and  these  are  less  differentiated  as  compared  with  the  cells  of  other 
regions.3  At  most  it  may  be  said  that  the  development  of  the  temporal 
lobe  is  also  very  conspicuous  in  apes  and  in  man,  so  that  the  fissure  of  Sylvius, 
which  is  vertical  in  the  brain  of  the  horse  and  of  the  ox,  becomes  inclined 
at  a  considerable  angle  in  the  brain  of  the  anthropoid  apes,  and  much  more 
so  in  the  case  of  man  in  whom,  indeed,  it  becomes  almost  horizontal.  The 
extraordinary  development  of  the  temporal  lobe,  which  remains  separated 
from  the  parietal  by  the  fissure  of  Sylvius,  gives  an  illusory  appearance 
of  great  size  to  the  parietal  lobe,  although  it,  too,  undoubtedly  shows 
development. 

My  conclusions  are  drawn  from  comparative  anatomy.  From  the  cat 
to  the  dog,  from  the  latter  to  the  macacus,  the  cebus,  the  gorilla,  and  finally 
to  man,  there  is  a  constantly  increasing  prominence  of  the  frontal  lobe,  which 

1  Sydney  Cole.     "  The  Comparative  Anatomy  of  the  Frontal  Lobe."     Journ. 
of  Ment.  Science.     1911. 

2  Jakob.     LOG.  cit. 

3  Vin.  Bianchi.     Loc.  cit. 


108  THE  MECHANISM  OF  THE  BRAIN 

assumes  the  appearance  of  a  new  region  in  relation  to  the  other  parts  of  the 
cerebral  mantle,  although  these  all  develop  and  increase  in  size,  especially, 
as  has  been  remarked,  the  temporal  lobe. 

That  the  parietal  has  not  attained  a  development  proportional  with  that 
of  the  frontal  lobe  had  already  been  noted  by  Broca,1  who  laid  stress  upon  the 
contrast  between  the  frontal  lobes  and  the  parietal  and  limbic  lobes  in  point 
of  development,  at  the  same  time  ascribing  to  the  frontal  lobes  the  higher 
faculties  predominant  in  intelligent  mammals. 

Meynert  maintains  the  view  that  the  great  proportions  attained  by  the 
frontal  lobes  are  more  apparent  than  real,  being  due  in  great  measure  to  the 
growth  in  height  of  the  corpus  striatum,  the  insula  and  the  temporal  lobe. 
There  is  some  measure  of  truth  in  this  so  far  as  the  influence  exercised  by 
the  temporal  lobe  is  concerned.  With  regard  to  the  corpus  striatum  it  is 
to  be  observed  that  a  great  part  of  the  substance  of  the  pre-frontal  lobe  is 
found  in  front  of  the  anterior  pole  of  the  corpus  striatum,  as  will  be  seen 
from  the  figures  in  Chapter  IV.  showing  vertical  sections  of  brains  that  were 
subjected  to  experimental  mutilations. 

It  is  needless  to  enter  into  great  detail  or  to  review  at  length  the  literature 
dealing  with  the  limits  and  conformation  of  the  frontal  lobes  in  man.  The 
position  may  be  summed  up  thus  :  On  the  external  aspect,  the  limits  of  the 
frontal  lobe  are  easily  defined.  They  are  the  fissure  of  Rolando  behind,  the 
fissure  of  Sylvius  below,  the  interhemispheric  fissure  above  and  within,  and 
the  free  extremity  of  the  pole  in  front.  It  is  only  when  we  seek  to  define 
the  limits  on  the  lower  or  orbital  surface  and  on  the  median  or  inter- 
hemispheric  aspect,  that  difficulties  arise. 

As  regards  the  external  surface,  it  is  well  to  clear  the  way  of  all  dis- 
cussions as  to  whether  or  not  the  ascending  frontal  convolution  belongs  to 
the  frontal  lobe.  The  arrangement  and  implantation  of  the  frontal  con- 
volutions are  such  that,  at  a  glance,  one  is  persuaded  that,  from  a  morpho- 
logical point  of  view,  it  is  the  fissure  of  Rolando,  and  not  the  pre-frontal 
sulcus,  which  forms  the  posterior  limit  of  the  frontal  lobe  and  that  the 
ascending  frontal  convolution  forms  a  part  of  the  frontal  lobe. 

The  morphological  features  of  the  surface  of  the  brain  do  not  coincide 
with  the  functional  facts.  In  other  words,  the  convolutions  and  sulci  neither 
constitute  nor  limit,  in  any  regular  fashion,  organs  with  specialised  and 
determined  functions.  The  detailed  study  that  has  been  made  of  the 
convolutions  and  sulci  forms  a  rich  and  brilliant  chapter  in  morphology, 
phylogenesis  and  ontogenesis  of  the  cerebral  mantle ;  it  has  been  utilised 
as  a  ground  for  contending  views  regarding  mental  pathology,  criminal 
anthropology  and  general  anthropology,  but  it  has  not  been  a  profitable 
chapter  in  the  physiology  and  pathology  of  the  brain.  All  attempts  based 
on  these  grounds  have  ended  in  failure  and  have  hindered  a  truer  conception 
of  the  functions  of  the  cerebral  cortex.  Each  individual  lobe  may  very  well 
be  composed  of  parts  having  different  functions  and,  further,  each  single 

1  Broca.  Localisations  cerebrales.  Recherches  sur  les  centres  olfactives,  et 
memoir es  sur  le  cerveau  de  VTiomme  et  des  primates.  1888. 


STRUCTURE  OF  THE  FRONTAL  LOBE  109 

convolution  may  have  different  parts  with  varying  cytotectural  features  and 
different  functional  and  psychic  arcs.  Indeed  these  two  propositions  can 
be  put  forward  with  a  fair  amount  of  assurance :  (1)  no  function  of  the 
cerebral  mantle  coincides  strictly  with  any  particular  region  that  is  denned 
on  a  purely  morphological  basis ;  (2)  the  indications  for  functional  areas 
can  be  determined  only  by  experiment  and  human  pathology,  though  in 
the  future  they  may  be  provided  also  by  cytotectural  studies.  When, 
therefore,  we  say  that  the  frontal  lobe  is  limited  behind  by  the  fissure  of 
Rolando  we  merely  speak  of  an  organ  the  different  parts  of  which  have 
different  functions.  The  ascending  frontal  convolution,  as  already  men- 
tioned, is  a  motor  area.  It  extends  behind  into  the  fissure  of  Rolando  and, 
in  front,  near  the  feet  of  the  three  frontal  convolutions,  it  merges  into  the 
area  now  known  as  the  precentral  intermediate  area. 

According  to  histologists  the  precentral  intermediate  area  occupies  a 
strip  of  the  pre-Rolandic  convolution  in  front  of  the  motor  area,  and  at  its 
upper  portion  it  extends  forwards  on  to  the  superior  frontal  convolution  for 
about  15  mm.  in  front  of  the  pre-Rolandic  sulcus.  Thence  it  describes  a 
curve  with  convexity  behind  to  a  point  near  the  centre  of  the  pre-Rolandic 
convolution,  curving  forward  again  on  to  the  third  or  inferior  frontal  con- 
volution (Figs.  44,  45,  area  6 ;  and  Figs.  46,  47,  area  MI)  and  extending  under- 
neath, on  the  orbital  aspect  of  the  frontal  lobe,  to  a  part  of  the  transverse 
portion  of  the  third  frontal  convolution.  It  thus  embraces  the  foot  of  the 
superior  and  middle  frontal  convolutions,  a  part  of  the  ascending  frontal, 
and  a  fairly  large  portion  of  the  inferior  frontal,  including  Broca's  area  and 
the  orbital  part  of  the  frontal  operculum.  These  limits  are  not  absolutely 
fixed  and  determined,  but,  according  to  Campbell,  are  fairly  easily  recognised. 
Campbell  insists  that  the  area  in  question  coincides  with  the  experimentally 
excitable  area  in  monkeys  and  that  its  limits  correspond  to  some  extent  with 
the  anterior  limits  of  the  so-called  somsesthetic  or  tactile  zone  of  Flechsig 
(Figs.  5  and  6).  In  monkeys  (cebidce)  I  have  found  the  anterior  portion  q, 
this  area  inexcitable  when  employing  a  current  just  sufficiently  strong,  when 
applied  to  the  ascending  frontal  or  pre-Rolandic  convolution,  to  induce  move- 
ments of  the  limbs,  except  in  the  case  of  the  first  frontal  convolution  where, 
over  a  considerable  area,  electrical  excitation  induces  movement  of  the 
trunk  and  head  (Fig.  51).  Campbell  supposes  that  all  this  area,  which  in 
structure  closely  resembles  the  motor  zone,  serves  for  the  more  specialised 
and  delicate  movements  in  which  consciousness  and  will  play  no  small  part. 
This,  he  thinks,  explains  why  the  foot  of  the  third  frontal  convolution  is  the 
central  organ  of  spoken  language  in  man,  and  that  of  the  middle  frontal, 
the  organ  of  other  more  delicate  and  complex  movements  of  the  fingers  such 
as  those  of  writing. 

The  view  which  has  just  been  expressed  and  which  agrees  with  that  of 
Mott l  and  with  the  view  put  forward  by  the  author  in  1883 2  when  he  regarded 

1  Mott.     "  On  the  Physiological  Significance  of  the  Convolutional  Pattern  in  the 
Primates."     Brit.  Med.  Journ.      1906. 

2  Bianchi.     Le  localizzioni  cerebrali.     Ed.  Pasquale.     Naples,  1883. 


110 


THE  MECHANISM  OF  THE  BRAIN 


that  area  as  a  zone  of  evolution,  is  not  supported  by  experiments  upon  the 
gibbon.  This  is  owing  to  the  fact  that,  in  the  brain  of  the  gibbon,  the  area 
in  question  covers  a  wider  extent  than  in  that  of  man,  especially  on  the  foot 
of  the  third  frontal  (experiments  of  Sherrington,  Schuster  and  Mott l),  a  fact 
which  takes  away  a  good  deal  of  value  from  the  physiological  interpretation 


Fig.  44. — Histotectural  geography  of  the  cerebral  cortex.     External  aspect 

(after  Brodmann) 


Fig.  45. — Histotectural  geography  of  the  cerebral  cortex.     Median  aspect 

given  to  this  area  by  Campbell,  because  it  is  obviously  in  man,  if  anywhere, 
that  one  should  expect  to  find  the  excitable  zone  attain  its  greatest  extent. 
It  is  sufficient  to  compare  the  great  extension  forward  of  the  motor  zone 
in  the  brain  of  the  gibbon,  which  has  been  explained  by  the  remarkable 
use  it  makes  of  its  hands  (Fig.  48),  with  the  corresponding  area  in  man  who 
makes  ever  so  much  more  use  of  his  hands  than  the  gibbon.     In  man,  the 
motor  zone  in  one  sense  extends  in  front  of  the  limits  of  the  ascending  frontal, 
although  in  another  sense  it  does  not.     The  contradiction  is  striking. 
1  Sherrington,  Schuster  and  Mott.     LOG.  cit. 


STRUCTURE  OF  THE  FRONTAL  LOBE 


111 


In  Figure  48,  e.g.,  the  larger  dots,  starting  from  the  fissure  of  Rolando, 
indicate  the  motor  area  which  contains  giant  pyramidal  cells  and  would 
correspond  to  the  true  motor  zone  or  Brodmann's  histotectural  type  No.  4 


SI    STI 


PRF 


SV 


20 


5T.T 


Fig.  46.— Histotectural  geography  of  cerebral  cortex.  .  External  aspect 
(after  Campbell 


STI 


STP     MP 


PRF 


VP  / 

STT  OLF 

Fig.  47. — Histotectural  geography  of  cerebral  cortex.     Median  surface 

(Fig.  44). J  The  smaller  dots  indicate  the  intermediate  motor  area  which 
would  correspond  to  the  type  marked  No.  6  in  Figure  44. 

I  have  personally  been  unable  to  satisfy  myself  regarding  these  distinctions 
even  in  my  most  recent  investigations. 

In  all  my  researches  I  have  investigated  the  whole  of  that  part  of  the 

1  Brodmann.  "  Beitrage  znr  histologischen  Legalisation  der  Grosshirnkinde." 
Journ.  fur  Psych,  und  Neurol.  1905. 


112 


THE  MECHANISM  OF  THE  BRAIN 


frontal  lobe  which  remains  in  front  of  the  pre-Rolandic  convolution,  including 
a  part  of  the  intermediate  motor  area.  This  region  comprises  the  two  areas 
distinguished  by  histologists  as  the  frontal  and  prefrontal,  besides  a  part 
of  the  intermediate  motor  zone.  The  structure  of  the  frontal  area  differs 
somewhat  from  that  of  the  pre-frontal  area,  properly  so  called.  On  the 
external  surface  of  the  hemisphere,  commencing  at  the  limits  of  the  inter- 
mediate zone,  the  frontal  area  extends  on  to  the  anterior  half  of  the  superior 
frontal  convolution,  embraces  a  good  part  of  the  middle  frontal,  and  takes 
in  the  anterior  extremity  of  the  inferior  frontal,  as  well  as  a  small  area  on 
the  orbital  surface.  On  the  interhemispheric  aspect  it  occupies  the  upper 
portion  of  that  part  of  the  superior  frontal  or  marginal  convolution  which 
lies  above  the  genu  of  the  corpus  callosum  (Fig.  48a).  It  differs  in  structural 


Z.M 


Z.P 


a.p.F 


Fig.  48. — Brain  of  gibbon 

R.  Fissure  of  Rolando. — ZM.  Motor  zone.— ZP.  Frontal  zone  in  continuation 
of  the  intermediate  area. — ZPF.  Pie-frontal  zone 

details  from  the  intermediate  area  for  there  is  an  almost  complete  absence 
of  fibres  of  large  calibre,  although  it  contains  some  of  medium  calibre. 
According  to  Campbell,  the  difference  is  most  marked  in  the  layer  of  large 
and  small  pyramidal  cells,  these  being  fewer  in  number  and  smaller  in 
size. 

The  pre-frontal  zone  includes  what  one  might  call  the  polar  part  of 
the  superior  frontal  convolution  on  the  interhemispheric  surface,  the  polar 
extremity  of  the  second  frontal  and  all  the  orbital  surface  situated  in 
front  of  the  transverse  orbital  sulcus  (Fig.  47).  According  to  Campbell, 
this  area  is  even.less  developed  than  the  frontal  area  and  the  fibres  it  contains 
are  very  few  in  number  and  very  fine  in  calibre.  The  association-fibres  are 
especially  deficient.  The  pre-frontal  area  might  be  said  to  be  still  in  process 
of  evolution,  its  development  being  very  late  as  compared  with  the  other 
areas  of  the  frontal  lobe.  There  is  a  marked  difference  between  primates 
and  man  in  the  structure  of  this  part  of  the  brain,  and  one  would  be  justified 
in  admitting  also  a  considerable  difference  in  development  in  different  men. 


STRUCTURE  OF  THE  FRONTAL  LOBE  113 

Bolton,1  on  the  other  hand,  maintains  that  the  structure  of  the  frontal  lobe 
closely  resembles  that  of  the  visuo-psychic  area.  There  is  the  same  number 
of  cell-layers  but  the  superficial  layer  shows  a  considerable  complexity  of 
fibrils.  The  second  layer,  that  of  the  pyramidal  cells  (the  smaller  external 
and  the  large  internal),  shows  a  wealth  of  cells  and  fibres  as  do  also  the  lower 
strata.  The  columns  of  Meynert  are  especially  in  evidence  and  contain 
many  large  fibres.  Bolton  arrives  at  the  conclusion  that,  so  far  as  richness 
in  neuro-fibrils  is  concerned,  the  prefrontal  region  probably  excels  all  other 
regions  of  the  cortex.  The  fact  that  the  frontal  lobe  is  the  last  region  of  the 


Z.F 


.Z.P.F 


Fig.  48a. — Median  aspect  of  the  cerebral  hemisphere 

ZT.  Tactile  area.— ZM.  Motor  area.— ZMT.   Intermediate  motor  area.— ZF.  Frontal  area.— 
ZPF.  Pre-frontal  area 

brain  to  develop  gives  ground  for  regarding  it  as  an  organ  of  great  importance 
for  intellectual  functions. 

Bolton  thus  obtained  results  very  different  from  those  of  Campbell,  whose 
methods  he  considered  defective.  His  findings,  however,  agree  with  those 
of  Turner,  who  also  found  a  remarkable  richness  of  fibres  and  cells  in  the  area 
in  question. 

These  results  seem  all  the  more  worthy  of  consideration  in  respect  that 
the  layer  of  pyramidal  cells  in  the  frontal  lobe  is  the  last  to  be  developed, 
a  finding  which  agrees  with  the  results  of  the  investigations  of  Watson  2 
and  Brodmann.3 

It  is  a  remarkable  fact  that  the  layer  of  pyramidal  cells  is  found  more 
or  less  sub-evolved  in  phrenasthenics  in  proportion  to  the  degree  of  imbecility 
or  idiocy,  and  it  is  the  first  cerebral  organ  to  undergo  the  degenerative  process 
in  the  various  forms  of  dementia,  a  fact  which  is  in  agreement  with  the 

1  Bolton.     "  A  Contribution  to  the  Localisation  of   Cerebral  Function."     The 
CrOttZstonwm  Lectures.     1910. 

2  Watson.     "  The   Mammalian  Cerebral   Cortex  with   Special  Reference  to  its 
Comparative  History."     Arc.  of  N enrol.     1907. 

3  Brodmann.      Uber  den  allgemeinen  Bauplan  des  Cortex  Pallii  bei  den  Mamma- 
Hem  und  zivei  Homologe  Rindenfelder  in  Besonderen,  etc.     Mitteilungen,  1906. 

H 


114 


THE  MECHANISM  OF  THE  BRAIN 


general  law  that  dissolution  proceeds  in  the  inverse  order  of  evolution. 
The  first  organs  to  degenerate  are  those  which  were  the  last  to  appear  in  the 
evolutionary  scale.  Flechsig's  researches,  which  have  demonstrated  the 
lateness  in  maturity  of  the  fibres  of  the  frontal  lobe,  are  in  agreement  with 
those  of  Campbell,  Bolton  and  Brodmann. 

The  orbital  surface  of  the  frontal  lobe  is  in  part  taken  up  with  anatomical 
relations  with  the  olfactory  tract  and  bulb.  The  first  frontal  or  internal 
convolution  on  the  orbital  surface,  or,  rather,  that  part  of  it  known  as  the 


•c.f.o 


1'C.F.O 


Fig.  49.— Inferior  orbital  surface  of  the  frontal  lobe 

gyrus  rectus  (CR  Fig.  49),  is  limbic  in  its  structure.  With  regard  to  the 
orbital  portions  of  the  other  two  frontal  convolutions  (the  middle  or  second 
frontal  2  :  CFO  and  the  third  frontal  3  :  CFO),  which  are  regarded  by 
anatomists  as  the  prolongations  of  the  second  and  third  frontal  convolutions 
on  the  orbital  base  (Dejerine),1  nothing  is  definitely  known  of  their  functions, 
either  from  experiments  or  from  the  study  of  human  pathology.  They 
exhibit  a  structure  similar  to  that  of  the  external  surface  of  the  frontal 
and  pre-frontal  areas. 

From  the  morphological  point  of  view,  the  second  fronto- orbital  con- 
volution is  limited  behind  by  the  "  H  "-shaped  fissure  (Fig.  49).  The  third 
convolution  is  placed  horizontally,  bordering  the  second  and  forming  the 
transverse  branch  of  the  third  fronto -orbital  convolution  (3  :  CFO). 

1  Dejerine.     Anatomie  des  centres  nerveaux.     Vol.  i. 


STRUCTURE  OF  THE  FRONTAL  LOBE  115 

The  superior  frontal  convolution  with  a  part  of  its  orbital  surface  is 
separated  from  the  second  or  middle  frontal  by  means  of  the  superior  frontal 
sulcus,  and,  just  in  front  of  the  point  where  it  curves  round  to  the  orbital 
surface,  it  is  incised  by  the  fronto -marginal  sulcus  of  Wernicke  (sulcus  anterior 
transversus) .  It  then  proceeds  to  the  orbital  surface,  where  it  forms  the 
f  ronto-orbital  convolution  (1  :  CFO) .  The  part  of  this  internal  to  the  olfac- 
tory sulcus  is  known  as  the  gyrus  rectus.  Behind  and  above,  it  reaches  the 
para-Rolandic  lobule  on  the  interhemispheric  aspect  (Fig.  48a)  and  from  this  it 
is  separated  by  the  para-central  sulcus  which  anastomoses  with  the  calloso- 
marginal  sulcus.  As  the  latter  is  not  prolonged  upwards  in  many  brains, 
the  interhemispheric  margin  of  the  first  or  superior  frontal  convolution  is 
continued,  without  morphological  distinction,  into  the  para-Rolandic  lobule 
(Figs.  48a  and  3).  In  the  brain  photographed  (Fig.  48a),  it  happens  that  the 
para-Rolandic  sulcus  is  prolonged  upwards  to  the  interhemispheric  margin 
so  that  the  superior  frontal  convolution  appears  definitely  separated  from 
the  para-Rolandic  lobule. 

The  middle  or  second  is  separated  from  the  superior  frontal  convolution 
by  the  superior  frontal  sulcus  above,  from  the  inferior  or  third  frontal  con- 
volution by  the  inferior  sulcus  below.  Behind,  it  is  implanted  upon  the 
ascending  frontal  from  which  it  is  often  partly  separated  by  the  inferior 
branch  of  the  pre-frontal  sulcus.  In  front,  it  curves  round  to  the  orbital 
surface,  going  as  far  as  the  transverse  branch  of  the  third  frontal.  Like  the 
superior,  it  also  is  incised  transversely  by  the  fronto-marginal  sulcus  at  the 
frontal  pole.  It  is  often  divided  into  two  by  a  sulcus  parallel  with  the  two 
frontal  sulci. 

The  third  or  inferior  frontal  convolution  forms  many  folds  around  the 
horizontal  and  the  vertical  branch  of  the  fissure  of  Sylvius.  On  the  orbital 
surface,  it  is  found  situated  transversely  behind  the  sulcus  of  the  "  H  "- 
shaped  fissure.  It  begins  at  the  posterior  extremity  of  the  olfactory  sulcus, 
curves  upwards  and  is  folded  around  the  branches  of  the  Sylvian  fissure  to 
be  implanted  on  the  ascending  frontal.  Often  it  receives  above,  in  one  of 
the  "  M  "-shaped  foldings,  the  inferior  pre-frontal  sulcus.  It  is  divided  into 
three  parts,  the  inferior  comprising  the  horizontal  orbital  portion  (from  the 
olfactory  sulcus  to  the  anterior  horizontal  branch  of  the  fissure  of  Sylvius)  ; 
a  triangular  portion  on  the  external  aspect  of  the  hemisphere  (Broca's  con- 
volution) comprised  between  the  anterior  horizontal  branch  and  the  vertical 
or  ascending  branch  of  the  fissure  of  Sylvius  ;  a  third  part  situated  behind 
the  vertical  branch  of  the  fissure  of  Sylvius  and  forming  the  so-called  foot 
or  pars  opercularis  of  the  third  frontal. 

It  is  to  be  observed  that  the  plan  of  distinguishing  two  sulci  separating 
three  convolutions  on  the  external  surface  of  the  frontal  lobe,  though  adopted 
in  almost  all  the  more  recent  text-books  of  anatomy  of  the  nervous  centres, 
is  only  schematic.  Often  there  exists  only  one  very  distinct  sulcus,  the 
superior  or  the  inferior,  and  groups  of  sulci  or  segments  of  sulci  in  various 
situations.  The  latter  mode  of  disposition  of  the  sulci  and  of  the  convolu- 
tions of  the  frontal  lobe  has  been  observed  in  the  brains  of  Herero  and 


116  THE  MECHANISM  OF  THE  BRAIN 

Indians,  but  one  is  not  warranted  in  regarding  it  as  the  rule.  In  several 
hundred  brains  of  Campani 1  examined  by  the  writer  in  the  Naples  asylum, 
where  post-mortem  examinations  were  made  in  every  case,  he  almost  always 
succeeded  in  singling  out  the  two  chief  frontal  sulci.  The  third  sulcus 
which  divides  the  second  frontal  convolution  into  two  was  also  frequent,  as 
well  as  groups  of  secondary  and  tertiary  sulci  running  in  different  directions. 

The  author's  particular  field  of  study,  so  far  as  this  work  is  concerned, 
has  comprised  all  the  frontal  lobe  in  front  of  the  motor  zone,  properly  so 
called,  including  the  orbital  surface  of  the  second  frontal,  the  external 
orbital  portion  of  the  first  frontal,  and  sometimes  the  transverse  portion  of 
the  third  frontal.  To  avoid  ambiguity  and  complications  the  writer  is  bound 
to  admit  that  he  has  hardly  ever  included  the  orbital  plane  of  the  frontal 
lobe  in  his  experimental  destructions,  nor  has  he  taken  account  of  the 
histological  fields. 

We  can  speak  of  all  that  region  situated  in  front  of  the  ascending  frontal 
convolution  as  pre-Rolandic.  It  is  divisible,  according  to  experimental 
indications,  into  three  areas.  We  can  take  the  pre-frontal  sulcus  as  the  line 
separating  the  Rolandic  region  from  the  pre-Rolandic  area,  which  in  monkeys 
would  include  a  part  of  the  intermediate  zone  ;  but  this  line,  passing  as  it 
does  through  the  points  of  insertion  of  the  frontal  convolutions  into  the  pre- 
Rolandic,  is  only  an  ideal  one.  The  pre-frontal  sulcus  has  not  always  the 
same  length,  nor  the  same  inclination.  It  is  found  farther  behind  or  farther 
forwards  in  different  individuals  of  the  same  species,  as  is  well  exemplified 
in  the  case  of  the  cebidse  (vide  Figs.  41,  42,  43). 

In  monkeys  from  the  Red  Sea  littoral,  the  pre-frontal  sulcus  is  placed  much 
farther  forwards  than  in  the  primates  and  in  man.  Between  the  motor  area 
and  the  frontal  area,  properly  so  called,  in  which  we  find  points  of  electrical 
excitability  for  the  eyes,  pupils  and  ears,  there  exists  in  the  majority  of  cases 
an  inexcitable  strip  or  zone.  In  these  monkeys  this  area  is  found,  as  a  rule, 
behind  the  pre-frontal  sulcus.  It  is  the  area  which,  on  experimental  grounds, 
can  competently  be  called  the  intermediate  motor  zone.  Thus,  proceeding 
from  behind  forwards,  we  meet  with  (a)  the  zone  for  the  limbs  (anterior 
Rolandic)  ;  (b)  an  intermediate  motor  zone  which  is  inexcitable  with  weak 
electric  currents ;  (c)  a  frontal  zone,  properly  so  called,  which  has  some 
excitable  points  and  apparently  also,  some  cytotectural  peculiarities ; 
(d)  the  pre-frontal  area. 

Taking  a  general  survey  of  the  development  of  the  cortex,  the  frontal  lobe 
presents  certain  peculiarities,  as  is  evidenced  by  Bolton's  studies.  The 
development  takes  place  from  within,  outwards — that  is  to  say,  from  the 
deeper  layers  to  the  surface.  As  a  matter  of  fact  the  superficial  layer  and 
that  of  the  pyramidal  cells  (external),  in  a  foetus  of  six  months,  have  only 
half  the  thickness  they  attain  in  the  adult.  The  growth  is  due  to  fission  of 
the  neuroblasts  in  an  upper  and  a  lower  part,  a  fact  which  is  of  some  con- 
siderable significance.  The  development  of  the  various  layers  of  the  cortex 

1  Inhabitants  of  the  Campania — i.e.  the  district  comprising  the  provinces  of 
Naples,  Caserta  and,  in  part,  Salerno. 


STRUCTURE  OF  THE  FRONTAL  LOBE  117 

differs  in  different  functional  zones,  and  Bolton  maintains  that  lie  has  good 
grounds  for  his  contention  that  development  takes  place  in  the  visuo-sensory 
area  before  it  occurs  in  the  visuo-psychic  area,  and  in  the  latter  before  the 
pre-frontal  region.  He  insists  on  the  importance  of  the  granular  layer  and 
maintains  that  in  the  visuo-sensory  area  individual  differences  are  related 
to  the  power  of  receptivity,  whilst  the  layer  of  pyramidal  cells  would  be  the 
physical  basis  of  the  associative  and  voluntary  processes.  When  this  layer 
in  the  frontal  lobe  is  thinner  than  the  mean  normal,  this  would  signify 
sub-evolution  of  this  lobe,  a  condition  which  is  found  most  marked  in  amentia 
(phrenasthenia) .  The  thickness  of  this  layer  in  the  frontal  lobe  varies  directly 
with  the  degree  of  imbecility  or  idiocy.  In  normal  evolution  this  layer  is 
last  of  all  to  be  evolved.  Further,  it  is  very  poorly  developed  in  lower 
mammals  and  shows  a  progressive  evolution  as  we  rise  in  the  mammalian 
scale.1  Contrary  to  what  we  observe  in  the  evolution  of  the  cortex  (from 
within  outwards),  in  dissolution  the  process  makes  its  appearance  first  in 
the  pyramidal  cell  layers,  thus  confirming  the  general  law  that  dissolution 
begins  first  in  those  organs  that  developed  last  in  the  evolutionary  series. 

Apart  from  the  little  the  writer  has  reported  in  the  preceding  pages,  the 
study  of  cytotecture  has  not  furnished  us  with  positive  data  on  which  we 
can  build  and  support  any  hypothesis.  Without  entering  into  great  detail 
one  may  briefly  review  all  the  more  interesting  findings. 

Schafer,2  from  the  histological  point  of  view,  divides  the  frontal  lobe  into 
three  regions.  The  first  is  the  region  next  to  the  ascending  frontal  and 
includes  the  intermediate  zone  of  Campbell  and  a  part  of  the  frontal  area, 
properly  so  called.  The  second  is  that  of  the  pole,  which  extends  backwards 
to  the  area  called  by  others  pre-frontal  (inexcitable),  and  this  region  he  found 
to  be  poorly  provided  with  fibres.  The  third  is  the  basal  or  orbital  region 
which  is  rich  in  fibres. 

Hammerberg  3  found  the  intimate  structure  of  the  frontal  convolutions 
to  vary  as  he  proceeded  forwards  from  the  bases  towards  the  frontal  pole. 
He  found  cell-layers  becoming  thinner  whilst  the  pyramidal  cells  became 
smaller  and  fewer  in  number. 

According  to  Betz,  the  orbital  part  of  the  second  frontal  convolution 
does  not  differ  in  structure  to  any  great  extent  from  the  external  surface. 
The  gyrus  rectus,  however,  he  found  to  resemble  the  limbic  lobe  in  structure. 

Brodmann4  distinguishes  eight  areas  in  the  frontal  lobe,  in  the  human 
subject,  each  of  which  can  be  subdivided  into  several  myelogenetic  areas. 

Vogt  obtained  results  which  agree  in  some  fundamental  respects  with 
those  of  Brodmann  yet  differ  in  many  points.  • 

Jakob  5  distinguishes  three  or  four  sectors  in  the  frontal  lobe  excluding 

1  Watson.     "  The  Mammalian  Cerebral  Cortex,  with  Special  Reference  to  its 
Comparative  Histology.     Arch,  of  N em.     1907. 

2  Schafer.     Mentioned  by  Bonne.     L'Ecorce  cerebrale.     1910. 

3  Hammerburg.     Studien  iiber  Klinik  u.  Pathologic  der  Idiotie,  etc.     Upsala,  1895. 

4  Brodmann.      "  tJber    den    allgemeinen    Bauplan    des    Cortex    Pallii    bei    den 
Mammaliern,"  etc.     Journ.  fur  Psychol.  und  N  enrol. 

6  Jakob.      Vom  Tierhirn  zum  Menschenhirn.     1911. 


118  THE  MECHANISM  OF  THE  BKAIN 

the  pre-Rolandic  convolution — the  fronto-polar,  the  anterior,  middle  and 
posterior  sectors.  He  is  of  opinion  that  the  process  of  differentiation  in  the 
majority  of  sectors  of  the  neopallium  is  simultaneous  with  the  progress  of 
intelligence. 

Roncoroni x  agrees  neither  with  Vogt  nor  with  Brodmann. 

This  brief  reference  to  the  present  position  of  cytotecture  and  myelotecture 
is  sufficient  to  convince  us  that  we  are  still  far  from  possessing  precise  know- 
ledge as  to  the  intimate  structure  of  the  frontal  lobe.  There  is  no  agree- 
ment or  correspondence  in  point  of  form,  number  or  disposition  of  the  cells 
of  the  various  zones.  Myelogenesis  and  cytoarchitecture  are  not  in  a  position 
at  present  to  define  the  histological  fields  of  differentiated  function.  They 
are  alluring  and  promising  sources  of  study  and  suggest  new  fields  for  the 
further  investigation  of  mental  affections  on  which  it  may  yet  be  possible 
to  build  up  a  psychology,  normal  and  pathological,  on  an  anatomical  basis. 

The  frontal  lobe  is  still  in  process  of  evolution,  even  in  man  himself. 
This  has  been  borne  out  by  some  recent  researches.  In  a  comparative  study 
of  the  sagittal  sulci  of  the  frontal  lobe  in  the  brains  of  Indians,  Japanese, 
and  Herero,  the  anastomoses  of  the  principal  sulci  with  accessory  or  secondary 
sulci  at  the  upper  and  lower  borders  of  the  frontal  lobe  were  found  to  be 
most  numerous  in  the  Japanese,  whilst  in  Indians  these  anastomoses  occurred 
only  in  the  upper  portion,  and  in  the  Herero  were  entirely  lacking.  From 
these  observations  Sergi 2  concludes  that  the  frontal  lobe  of  the  Japanese  is 
more  evolved  than  that  of  the  Indian  or  the  Herero. 

The  measure  of  the  distance  from  the  superior  and  inferior  extremities 
of  the  Rolandic  fissure  to  the  frontal  and  occipital  poles,  taken  on  the  average, 
has  demonstrated  a  greater  absolute  development  of  the  frontal  lobe,  always 
upwards  on  the  left  side  and  downwards  on  the  right.  Further,  the  develop- 
ment of  the  frontal  lobe  in  toto  is  greater  in  males  than  females.  There  thus 
exists  a  marked  variability  in  the  morphology  of  the  superior  and  inferior 
zones  of  the  frontal  lobe  in  different  races  between  the  two  sides  and  the  two 
sexes. 

Furthermore,  the  greater  development  of  the  frontal  lobe  upwards  on 
the  left  and  downwards  on  the  right  side  holds  good  in  both  sexes  (Italians, 
Germans,  etc.).  The  author  himself  has  not  carried  out  investigations  in 
this  direction  but  the  measurements  taken  by  S.  Sergi  from  the  superior 
and  inferior  extremities  of  the  fissure  of  Rolando  to  the  frontal  and  occipital 
poles  in  brains  of  Indians,  Japanese  and  Javanese,  due  allowance  being  made 
for  individual  as  well  as  well-marked  racial  variations,  indicate  the  remark- 
able development  of  the  fronto-Rolandic  mass  in  man.  It  has  been  shown, 
too,  that  not  only  is  there  variability  in  the  development  of  the  left  frontal 
lobe  as  compared  with  the  right,  but  also  the  oscillations  to  right  and  to  left 
are  wider  in  females  than  in  males,  and  that  the  development  of  the  frontal 

1  Roncoroni.     Loc.  cit. 

2  Sergi.     Note  morjologiche  sulla  superficie  metopica  dei  lobi  frontale  in  cervelli  di 
indiani  e  di  giapponesi.     1913. 


STRUCTURE  OF  THE  FRONTAL  LOBE  119 

lobe  is  more  marked  on  the  left  side  in  males  of  the  Indian,  Japanese  and 
Javanese  races. 

It  is  not  improbable  that  the  index  of  variability  of  the  frontal  lobe  differs 
in  different  ethnic  groups  as  well  as  in  the  sexes.  According  to  Sergi  the 
development  of  the  frontal  lobe  takes  place  by  growth  in  front  of  the  fissure 
of  Sylvius,  more  on  the  left  than  on  the  right  side.  This  would  go  to  confirm 
the  view  that  the  frontal  lobe  is  still  in  course  of  evolution. 

Clinical  observations  support  the  conclusion  that  the  left  frontal  lobe  is 
of  much  more  value  in  the  mental  processes  than  the  right.  Phelps  holds 
that  there  is  an  entire  absence  of  intellectual  or  other  function  in  the  right 
frontal  lobe.  Years  ago  Hughlings  Jackson  postulated  the  existence  of  a 
power  of  control  on  the  part  of  the  anterior  brain  over  the  highest  mental 
functions,  and  maintained  that  the  anatomical  substratum  of  these  mental 
operations  might  be  the  left  pre-frontal  lobe.  One  of  the  first  clinical 
indications  in  this  regard  is  to  be  found  in  the  observations  of  Starr, 
who,  as  a  matter  of  fact,  had  not  specially  directed  his  attention  to  the 
mental  symptoms  presented  by  patients  suffering  from  tumour  or  abscess 
of  the  frontal  lobes. 

In  dealing  with  this  subject  we  are  surrounded  with  difficulties  because 
it  is  not  easy  in  all  cases  to  estimate  the  precise  extent  of  the  primary  lesion, 
the  presence  or  absence  of  secondary  lesions,  the  existence  of  vascular 
alterations  (especially  in  cases  of  syphilitic  tumour  of  the  frontal  lobes), 
the  degree  of  compression  etc.  (cases  reported  by  Mills).  Phelps  supports 
the  view  that  the  left  frontal  lobe  fulfils  a  high  mental  function,  because 
of  the  important  relations  between  high  intellectual  function  and  language, 
which  is  a  function  of  the  left  hemisphere.  He  reasons  as  follows : — "  If 
articulate  speech  is  localised  in  the  left  frontal  lobe  and  only  exceptionally  in 
the  right  and  if  articulate  language  represents  one  of  the  mechanisms  for 
the  expression  of  thought,  one  need  have  no  difficulty  in  ascribing  to  the  left 
frontal  lobe  one  of  the  highest  cerebral  functions  such  as  that  of  the  control 
of  thought."  This  argument  is  contradicted  by  the  fact  that  the  functioning 
of  the  intellect  does  not  depend  upon  normal  conditions  of  the  cortical 
motor  organ  of  language  (taking  the  existence  of  this  as  incontestable),  but 
on  its  cortical  sensory  organs,  auditory  and  visual,  as  already  mentioned. 
Thus  it  is  that  in  the  few  cases  of  true  motor  aphasia  reported  in  the  literature 
of  the  subject  there  was  complete  mental  integrity,  in  so  far  as  internal 
diction  (the  motion  of  thought)  remained  possible. 

The  writer  has  had  no  means  of  confirming  this  hypothesis  in  the  course 
of  his  experiments.  The  differences  met  with  after  experimental  destruction 
of  the  right  and  left  frontal  lobes,  in  monkeys  of  the  same  family,  do  not 
warrant  him  in  giving  unconditional  support  to  this  view.  Shepherd  has 
been  more  fortunate  than  the  author  in  finding  a  decided  difference  between 
the  results  of  the  destruction  of  the  left  and  of  the  right  hemisphere, -such  a 
difference  as  has  warranted  him  in  stating  very  definitely  that  mental 
disturbances  are  much  more  frequently  a  result  of  destruction  of  the  left 
pre-frontal  lobe  than  of  the  right.  A  slight  difference  was  also  observed  by 


120  THE  MECHANISM  OF  THE    BRAIN 

the  author,  but  subsequent  post-mortem  examination  of  the  animals  experi- 
mented upon  did  not  always  convince  him  that  the  extent  of  the  mutilation 
permitted  a  comparative  judgment.  Even  admitting  it  to  be  an  actual  fact, 
it  can  be  explained  because  of  the  functional  differentiation  of  the  left  as 
compared  with  the  right  hemisphere,  and  not  because  the  frontal  lobe  is  the 
organ  of  language  and  indirectly  therefore  an  organ  regulative  of  intellect, 
for  the  motor  area  of  language  does  not  exercise  any  real  regulative  power 
either  on  the  formation  or  on  the  movement  of  thought.  The  hypothesis 
has  had  its  origin  in  the  fact  that  the  mental  disturbances  are  probably  due, 
at  least  in  part,  to  the  presence  of  a  tumour  which,  owing  to  compression 
or  vascular  disturbances,  affects  all  the  left  hemisphere.  In  such  cases  there 
is  a  great  liability  to  disturbance  and  disorder  of  the  auditory  sphere  of 
language,  which  is  one  of  the  main  wheels  in  the  logical  movement  of  thought. 


CHAPTER  IV 

Methods  of  Inquiry 

THE  investigation  of  a  problem  so  abstruse  and  delicate  as  that 
concerns^  the  function  of  the  frontal  lobe,  a  problem  of  the  highest  interest 
to  physiology  and  psychology  and  the  applications  of  these  to  clinical 
medicine  and  to  pedagogy,  demands  a  calm  and  dispassionate  mind  to  ensure 
that  facts  will  have  due  control  over  aprioristic  conceptions. 

Realising  that,  even  in  the  case  of  men  of  science,  who  sometimes  import 
a  great  deal  of  passionate  enthusiasm  into  their  studies,  the  mental  organisa- 
tion is  such  that  preconceptions  often  give  rise  to  illusory  visions  of  proofs, 
it  has  been  the  desire  of  the  author  to  avoid  this  error  as  far  as  possible 
and  to  retra verse  the  ground  of  inquiry  on  repeated  occasions.  He  has 
interrupted  his  experiments  for  one,  two  or  more  years,  and  taken  them 
up  again  in  series,  taking  stock  of  all  criticisms  and  modifying  his  methods 
so  that  he  might  be  better  able  to  state  the  facts  of  the  case  positively,  at 
the  same  time  giving  the  greatest  possible  consideration  to  the  objections, 
sometimes  rather  formidable,  put  forward  by  physiologists,  who,  by  reason 
of  their  authority,  succeeded  in  having  the  author's  views  rejected. 

The  investigator  who  performs  a  large  number  of  experiments  with 
fairly  uniform  results  experiences  a  calm  confidence  which  it  is  useless  to 
expect  from  a  few  experiments  with  hasty  conclusions,  of  which  there  are 
not  a  few  examples  in  the  literature  of  this  subject. 

Many  objections  have  been  urged  against  the  author's  views,  and  his 
experimental  methods  have  been  so  criticised  that  the  conclusions  drawn 
from  them  have  been  robbed  of  a  good  deal  of  value.  It  is  necessary  to 
take  some  brief  notice  of  these  criticisms. 

Schafer,1  Monakow  2  and  others  have  objected  that,  after  experimental 
lesions  of  the  brain,  the  effects  are  not  limited  solely  to  the  injured  region. 
Besides  the  local  effects,  those  strictly  related  to  the  function  of  the  injured 
region,  the  injury  makes  itself  felt  also  at  a  distance,  producing  in  other 
parts  of  the  brain  circulatory  disturbances  and  functional  arrest.  There 
is  some  truth  in  this  criticism,  but  when  Schafer  asserts  that  the  intellectual 
disturbances  observed  secondarily  in  animals  mutilated  in  their  frontal 
lobes  are  dependent  on  the  operation  itself,  one  may  assuredly  reply  that 
this  is  an  assertion  which  is  incapable  of  proof.  I  recognise  that  destruction 
of  the  cerebral  substance  to  any  extent  in  any  region  of  the  brain  gives  rise 
in  some  cases  to  secondary  functional  disturbances  of  circulation  and  nutri- 
tion at  a  distance.  As  a  rule,  however,  these  secondary  symptoms  are  of 


1  Schafer.     Text  Book  of  Physiology.       Vol.  ii. 

2  Monakow.     Gehirnkrankheiten.     1905, 


121 


122  THE  MECHANISM  OF  THE  BRAIN 

short  duration  and  can  even  be  diagnosed  by  methodical  and  detailed 
examination  of  the  animals  experimented  upon,  if  these  are  re-examined, 
as  they  should  be,  for  weeks  and  months  after  the  operation.  Even  from 
the  time  of  my  earliest  experiments  I  have  taken  special  note  only  of  those 
symptoms  that  were  observed  a  considerable  time  after  the  cerebral 
mutilation. 

Schafer  has  laid  stress  on  the  fact  that  I  removed  the  frontal  lobes  from 
the  cranial  cavity,  and  expressed  the  opinion  that  this  complicated  matters 
by  introducing  mechanical  and  physical  disturbances  as  well  as  vascular 
disorders  and  disturbances  of  relations,  a  state  of  affairs,  he  declares,  "  which 
may  lead  to  erroneous  conclusions."  This,  if  I  may  say  so,  is  rather 
a  subjective  mode  of  judgment  on  the  part  of  that  eminent  English 
physiologist. 

As  a  matter  of  fact,  in  many  cases  the  frontal  lobes  were  not  removed 
in  toto.  As  a  rule  they  were  decorticated,  sometimes  the  pole  was  removed, 
but  the  orbital  surface  was  almost  always  spared.  On  rare  occasions  I 
succeeded  in  making  a  very  extensive  excision  of  the  frontal  lobe,  including 
the  interhemispheric  and  a  part  of  the  orbital  surface.  The  space  which 
remained  after  removal  of  the  cortex  became  filled  up  with  transudate,  by 
blood  and  later  by  exudate,  as  happens  in  all  analogous  reparatory  processes. 
The  animals  completely  recovered,  almost  all  of  them  living  for  many  months 
and  even  more  than  a  year.  Symptoms  ex  vacuo  were  never  observed.  In 
formulating  conclusions  I  left  out  of  account,  in  every  case,  the  symptoms 
presented  by  the  dogs  and  monkeys  during  the  first  few  days.  The  necessity 
for  this  was  shown  by  the  behaviour  of  the  animals,  which  revealed  always 
the  same  deficit  so  long  as  they  were  kept  alive,  a  deficit  afterwards  con- 
trolled by  post-mortem  examination.  Many  of  the  animals  experimented 
upon  were  quite  lively  from  a  few  hours  after  the  operation. 

Symptoms  at  a  distance  and  lesions  at  a  distance  may  be  present,  but 
there  is  no  need  to  confuse  either  one  or  the  other  with  the  definite  effects 
of  extirpation. 

Monakow l  introduces  a  formal  element  of  criticism  which  tends  to 
depreciate  to  some  extent  the  doctrine  of  localisation. 

He  starts  out  with  the  view  that  psychic  manifestations  are  the  resultant 
of  a  co-ordinated  complexus  of  factors  which  have  their  origin  in  different 
cortical  areas  with  different  functions  (fields  or  phases  of  elementary  psychic 
actions) .  It  seems  a  probable  hypothesis,  he  maintains,  that  when  any  one 
of  the  sensory  areas  becomes  destroyed,  this  is  followed  by  interdiction  and 
dysorientation  of  other  areas  which  function  in  concert  with  it  in  consequence 
of  an  anatomical  overlapping,  the  latter  being  damaged  by  the  experiment 
in  some  essential  part  or  else  interrupted  in  its  paths  of  communication  with 
the  various  mechanisms  co-operating  with  it.  In  diaschisis,  the  term  which 
Monakow  applies  to  this  mode  of  action,  we  recognise  an  old  friend  in  a  new 
guise. 

1  Monakow.     Loc.  cit. 


METHODS  OF  INQUIRY  123 

There  is,  in  fact,  such  a  network  of  fibres  between  neighbouring  and  also 
distant  convolutions  that  a  lesion  circumscribed  to  any  one  convolution 
does  injury  also  to  the  function  of  neighbouring  convolutions.  A  classical 
example  is  provided  by  Horsley.1  This  distinguished  surgeon  laid  bare  the 
motor  zone  in  a  patient  affected  by  athetosis  and  severe  convulsions  of  the 
upper  limb.  By  means  of  electrical  excitation  he  delimited  the  area  for 
movements  of  the  upper  limb  in  the  pre-Rolandic  convolution.  He  then 
removed  the  cortex  from  this  area  and  the  result  was  cessation  of  the  athetotic 
movements  which  were  now  replaced  by  paresis  and,  associated  with  this, 
disturbances  of  sensibility  in  the  limb.  As  the  sensory  disturbances  had 
almost  disappeared  after  the  lapse  of  a  year  and  the  few  that  remained 
could  be  ascribed  to  actual  lesions  of  the  fibres  of  the  post-Rolandic  con- 
volution, it  was  unnecessary  to  attribute  to  the  pre-Rolandic  convolution 
both  motor  and  sensory  function,  as  Horsley  concluded,  basing  his  conclusion 
merely  upon  the  fact  that  disturbances  of  sensibility  were  conspicuous 
soon  after  the  operation.  Horsley  desired  to  adhere  to  his  old  conviction 
and,  unfortunately,  did  not  compare  it  with  the  sound  observations  of 
Sherrington.  The  hemiansesthesia  was  evidently  a  symptom  of  diaschisis, 
and  there  is  good  reason  for  supposing  that  what  remained  of  the  disturb- 
ances of  sensibility  in  that  patient  was  due  to  an  actual,  though  limited, 
lesion  of  the  ascending  parietal  convolution. 

Remote  lesions  which  complicate  the  symptomatic  picture  are,  as  a  rule, 
recognisable  by  control  experiments,  when  they  are  not  mere  symptoms 
of  arrest  or  vaso-motor  symptoms,  which  generally  are  very  fleeting.  This 
certainty  in  diagnosis,  though  not  absolute,  depends  upon  the  methods 
followed,  more  especially  upon  the  accurate  and  systematic  investigation 
of  symptoms  in  the  animals  experimented  upon,  and  in  addition  upon  the 
method  of  successive  excitations,  with  measurement  of  the  electric  current 
employed,  controlled  by  successive  and  graduated  destruction  of  determined 
cortical  fields.  Above  all,  it  depends  upon  collateral  experiments.  Pro- 
ceeding in  this  manner  and  comparing  the  results  of  the  destruction  of 
different  areas,  one  is  able  to  separate  out  the  symptoms  that  are  strictly 
due  to  the  lesion  from  the  entire  syndrome  that  immediately  follows  upon 
the  operation  and  from  the  further  symptoms  that  result  from  subsequent 
operations. 

The  permanent  deficit  imprints  a  particular  character  on  the  animal 
operated  upon,  and  it  is  this  that  is  to  be  put  down  to  the  mutilation.  The 
author  has  always  had  recourse  to  post-mortem  examination  in  order  to 
determine  whether  the  symptoms  observed  during  life  depended  solely  upon 
the  experimental  lesion  or  upon  lesions  which  had  developed  in  other  parts 
of  the  brain  and  had  complicated  the  symptomatic  picture  observed  during 
life.  One  of  the  monkeys  upon  which  he  operated  presented  at  the  post- 
mortem examination,  which  followed  three  months  after  the  operation,  an 
extensive  and  symmetrical  softening  of  both  occipital  lobes.  In  a  dog  there 

1  Horsley.  "The  Function  of  the  So-called  Motor  Area  of  the  Brain."  The 
Linacre  Lectures.  Brit.  Med.  Journ.  1909. 


124  THE  MECHANISM  OF  THE  BRAIN 

was  found  complete  softening  of  the  hippocampal  convolutions  on  both  sides. 
Conditions  such  as  these  are  rare  but  can  be  diagnosed. 

The  effects  of  disturbances  ex  vacuo  have  certainly  been  exaggerated 
and  it  is  unnecessary  to  dwell  upon  them.  To  speak  of  symptoms  ex  vacuo 
being  present  one  or  two  months  after  the  operation  is  nonsense. 

Another  physiologist,  Shepherd,1  anxious  to  avoid  the  objection  raised 
by  Schafer  against  the  method  of  excision  and  removal  of  the  frontal  lobe 
adopted  by  the  author,  made  a  more  or  less  extensive  and  deep  incision  into 
the  frontal  lobe,  separating  it  from  the  remainder  of  the  brain,  but  leaving  it 
in  situ.  Yet,  from  the  analysis  of  all  his  experiments  and  the  examination 
of  all  the  diagrams  of  brains  of  monkeys  operated  upon  by  him,  it  seems 
clear  that  the  lesion  was  only  partial. 

His  diagrams,  8,  9, 10,  12,  15,  16,  17,  18,  etc.,  show  lesions  limited  to  the 
foot  of  the  superior  or  that  of  the  middle  frontal  convolution.  The  pre- 
frontal  area  was  certainly  not  completely  incised  and  detached  from  the 
rest  of  the  cerebral  mantle,  but  remained  in  continuity  with  the  Rolandic 
zone  by  means  of  the  second  frontal  or  the  superior  frontal  convolution  or 
parts  of  both  and  by  that  region  of  the  frontal  cortex  which,  on  the  external 
surface,  forms  the  frontal  operculum  and  may  be  considered  as  the  rudiment 
of  the  third  frontal  convolution,  in  middle-grade  Abyssinian  monkeys.  Yet 
the  results  obtained  by  the  physiologist  of  George  Washington  University 
were  conspicuous  and  confirmed  those  obtained  by  the  author.  It  is,  how- 
ever, just  because  a  good  part  of  the  frontal  lobe  was  spared,  in  one  series 
of  experiments,  that  this  investigator  found  that  in  some  monkeys  and  cats 
there  was,  to  some  extent,  a  recovery  of  attitudes  and  actions  which  they 
had  previously  learned,  but  had  forgotten  after  the  operation.  If  there  was 
any  re-education  it  could  only  be  attributed  to  the  part  of  the  frontal  lobe 
spared  by  the  operation ;  in  every  case  re-education  was  incomplete. 
Shepherd's  investigations  serve  as  a  very  important  control  of  the  author's 
conclusions. 

It  is  worthy  of  note  that  actions  and  attitudes  that  have  become  habitual 
in  particular  animals  are  neither  lost  nor  notably  altered  after  mutilation 
of  the  frontal  lobes,  and  this  is  especially  true  as  regards  the  simpler  actions 
and  those  of  emotive  origin.  This  explains  why  one  of  Shepherd's  monkeys 
which  lost  the  faculty  of  opening  the  lid  of  a  food-box  nevertheless  retained 
that  of  jumping  on  the  shoulder  of  the  investigator,  just  as  he  had  done 
before  the  operation.  The  capabilities  of  jumping,  of  walking  through  the 
room,  of  tearing  at  the  door  in  an  effort  to  escape,  of  climbing,  of  seeking 
food,  of  eating  with  more  or  less  rapidity,  and  the  sexual  instinct  (somewhat 
modified  in  the  mode  of  satisfaction),  are  retained  after  frontal  mutilation. 
It  is  different  in  the  case  of  faculties  that  have  been  acquired  as  the  result 
of  education.  That  is  an  important  fact  demonstrated  by  Shepherd,  and 
it  confirms  once  again  the  difficulty  of  arriving  at  a  judgment  as  to  the 
precise  loss  suffered  by  animals  that  have  been  experimented  upon. 
1  Shepherd.  "  On  the  Functions  of  the  Cerebrum."  The  Frontal  Lobes.  1907. 


METHODS  OF  INQUIRY  125 

The  difference  in  the  syndromes  according  to  the  areas  destroyed,  and  the 
proportionality  of  the  effects  of  serial  destructions,  offer  strong  arguments 
against  the  views  of  those  who  have  criticised  the  results  of  destruction  of 
the  frontal  lobes,  maintaining  that  many  of  the  symptoms  observed  have 
been  due  to  post-operative  shock.  It  is  to  be  remarked  that  many  animals 
present  no  symptoms  of  shock  after  the  operation,  more  especially  if,  cwteris 
paribus,  they  have  not  been  too  deeply  narcotised.  In  this  connection  it  is 
worthy  of  note,  as  the  author  has  pointed  out  since  1889,  that  destructions 
of  the  occipital  lobe,  the  motor  zone,  the  temporal  lobe,  and  the  parietal 
lobe,  give  rise  to  syndromes  that  differ  greatly  from  one  another.  Control 
experiments  carried  put  both  by  the  author  and  by  Shepherd  have  confirmed 
this  view.  Shepherd  explicitly  declares :  "  The  last  four  experiments 
coupled  with  those  that  were  previously  described  on  cats,  indicate  clearly 
that  the  loss  of  association  in  animals  consecutive  to  lesions  in  the  frontal 
regions  is  not  due  to  the  general  shock  effect  of  the  operation."  The  fact 
is  that  many  investigators  are  not  yet  convinced  that  the  symptoms  ob- 
served during  the  first  few  days,  and  even  more  particularly  during  the  first 
few  hours  subsequent  to  the  operation,  possess  no  real  value  for  or  against 
the  doctrine  of  the  cerebral  localisations.  One  has  to  keep  these  animals 
alive  for  many  weeks  and  months  in  order  to  be  able  to  define  the  true 
functional  deficit  that  can  justly  be  attributed  to  the  part  of  the  brain 
destroyed. 

It  is  a  cardinal  principle  in  clinical  medicine,  in  cases  of  cerebral 
haemorrhage  or  thrombosis,  not  to  make  an  immediate  pronouncement  as 
regards  the  exact  seat  and  extent  of  the  lesion,  and  consequently  as  regards 
the  physical  and  psychic  loss  that  will  be  permanent,  because  the  syndrome 
is  very  complex,  not  only  during  the  first  few  hours  but  also  during  the  first 
few  days  and  even  for  some  weeks  after  the  attack.  The  physician  who, 
at  the  bedside  of  the  patient  on  the  first  or  second  day  after  an  apoplectic 
attack,  when  coma  has  passed  off,  pronounced  a  judgment  as  to  the  extent 
and  gravity  of  the  focus  (finding,  e.g.,  right  hemiplegia  and  sensory  aphasia), 
and  expressed  his  opinion  that  the  patient  was  in  a  very  serious  condition 
and  unlikely  ever  to  attend  to  his  business  again,  would  find  himself  in  an 
awkward  situation  after  a  few  days  or  weeks  when  the  patient  was  again 
capable  of  understanding  what  was  said  to  him  and  of  expressing  correctly 
his  own  thoughts.  If  more  rational  methods  had  always  been  followed  in 
experimental  investigations  upon  the  brain,  we  should  have  been  spared 
many  useless  discussions,  and  the  physio -pathological  literature  of  the 
cerebral  localisations  would  have  been  less  encumbered,  more  sincere,  and 
at  the  same  time  more  convincing.  Fortunately,  clinical  medicine  has  had 
its  conquests  and  has  accumulated  material  of  incalculable  value  not  only 
in  its  own  provinces  but  more  especially  in  its  practical  application  to 
anatomical  physiology,  psychology,  semeiology  and  surgical  therapy. 

It  has  to  be  borne  in  mind  that  in  nine  out  of  ten  animals  operated  upon 
symptoms  of  shock  are  non-existent,  or  else  insignificant  as  compared  with 
the  results  of  apoplexy  or  cerebral  trauma.  Further,  animals  that  have 


126  THE  MECHANISM  OF  THE  BRAIN 

suffered  mutilation  of  different  cortical  areas  exhibit  marked  differences  in 
behaviour.  Especially  noteworthy  is  the  variance  between  the  mental 
picture  presented  by  a  dog  mutilated  in  the  anterior  brain  and  that  by 
others  mutilated  in  the  parietal  or  temporal  or  occipital  lobes. 

Sciamanna  1  unwittingly  provided  a  strong  argument  against  the  shock 
hypothesis.  He  had  denied  the  existence  of  any  special  psychic  function 
in  the  frontal  lobes  but  it  was  found  at  the  post-mortem  examination  that 
he  had  removed  only  small  portions  of  these.  This  fact  could  be  utilised 
to  explain  the  absence  of  marked  disturbances  of  intelligence,  but  at  the 
same  time  it  provided  evidence  to  show  that  the  symptoms  of  shock  con- 
secutive to  the  operation  had  been  greatly  exaggerated.  More  recently, 
Shepherd  has  again  taken  up  the  question  and  has  given  further  proof  of  the 
fact  that  a  surgical  operation,  consisting  of  trephining  of  the  skull  and 
incision  of  the  dura  mater,  carried  out  under  all  the  ordinary  rules,  avoiding 
injury  to  the  cerebral  substance,  does  not  give  rise  to  any  of  those  disturb- 
ances that  generally  follow  lesions  of  determined  parts  of  the  brain.  The 
results  of  Bechterew's  researches  in  dogs  led  to  the  same  conclusions.  The 
author's  control  experiments  have  demonstrated  the  fact  that  lesions  of 
one  lobe  only,  and  also  very  limited  lesions  of  both  frontal  lobes,  in  monkeys, 
do  not  give  rise  to  appreciable  damage,  although  the  operation  itself  is  equally 
serious  in  all  cases. 

Functional  compensation  provides  another  source  of  error,  for  we  cannot 
altogether  deny  the  fact  'that  symptoms  of  compensation  may  enter  upon  the 
scene.  The  disappearance  of  some  of  the  symptoms  produced  by  a  spon- 
taneous lesion  of  the  brain,  or  by  experimental  lesion  in  the  brain  of  a  dog 
or  monkey,  is  due  in  part  to  the  compensating  action  of  analogous  areas  of 
the  healthy  hemisphere  or  of  the  areas  surrounding  the  focus.2 

There  are  functions  in  the  expressive  mechanism  of  which  both  hemi- 
spheres co-operate.  This  co-operation  varies  with  different  functions  and 
different  animals.  For  example,  compensation  of  experimental  paralysis 
is  much  slower  and  less  marked  in  monkeys  than  in  dogs,  whilst  in  the  human 
subject  compensation  of  paralysis  arising  from  a  spontaneous  cerebral  lesion 
is  still  much  more  difficult.  Indeed,  the  less  differentiated  is  the  cerebral 
mantle,  the  readier,  cceteris  paribus,  is  the  compensation  of  a  destructive 
lesion.  In  the  case  of  the  human  brain,  the  higher  functions,  such  as  that 
of  language,  can  be  compensated  in  some  measure  more  readily  than  the 
motor  function.  This  is  to  be  accounted  for,  to  some  extent,  by  the  fact 
that  the  language-area  is  very  extensive.  Partial  compensation  always 
occurs  when  only  one  part  of  the  entire  sensory  area  of  language  is  destroyed. 
Thus  it  happens  that,  in  the  long  run,  the  sensory  or  motor  aphasic  readjusts 

1  Sciamanna.     Loc.  cit. 

2  L.     Bianchi.     "  Le    compensazioni    funzionali    del    mantello    cerebrale.     La 
Psichiatria,  la   Neuropatologia  e  le  Scienze  affini.      1883.     Also  "  Le  malattie  del 
cervello "  in  Trattato  di  Patologia  Medica,  by  Maragliano  and  Cantani.     Vol.  ii., 
part  2. 


METHODS  OF  INQUIRY  127 

his  relations  with  the  social  world  by  means  of  language,  as  the  result  of  a 
fairly  strong  compensatory  action  of  the  parts  surrounding  the  focus  in  the 
left  hemisphere,  or  of  the  homologous  parts  in  the  right  hemisphere.  So 
true  is  this,  that  if,  after  improvement  in  the  function  of  language  has  taken 
place,  the  patient  becomes  the  victim  of  another  destructive  focus  in  the 
symmetrical  region  of  the  other  hemisphere  or  the  surrounding  parts  of  the 
same  hemisphere,  language  may  be  suppressed  for  all  time. 

Besides  symptoms  of  diaschisis,  dependent  upon  disturbance  of  functional 
equilibrium,  and  symptoms  of  compensation,  we  may,  after  a  lapse  of  time, 
get  secondary  degenerations  starting  in  the  area  destroyed  (Dejerine,1 
Bianchi  junior2).  Degenerative  processes  complicate  the  clinical  picture 
and  may  lead  us  into  the  error  of  attributing  to  the  experimental  lesion  what 
is  really  an  effect  of  the  secondary  degenerations  in  the  brain.  Between  the 
first  stage,  that  of  shock  and  diaschisis,  the  signs  of  which,  if  present  at  all, 
are  very  early  manifested,  and  the  last  stage,  the  signs  of  which  are  late  in 
appearance,  there  is  a  period  during  which  the  clinical  picture  is  constantly 
the  same  in  its  general  lines,  and  the  signs  then  met  with  must  be  put  down 
to  the  effect  of  the  experimental  lesion  itself. 

Notice  must  be  taken  of  another  prejudice.  It  has  been  objected  that 
the  mental  functions  of  animals,  even  of  the  higher  mammals,  are  not  to  be 
confused  with  those  of  man  and  that  no  serious  conclusion  can  be  drawn 
from  the  symptoms  observed  in  them,  such  as  would  allow  us  to  ascribe 
analogous  functions  to  determined  sections  of  the  cerebral  cortex  in  man. 
The  objection  seems  a  formidable  one.  When  we  confront  the  problems 
of  intelligence  we  should  not  seek  to  solve  them  except  by  study  of  man 
himself,  normal  and  pathological.  I  am  of  opinion,  however,  that  no  biologist 
who  attacks  these  problems  can  to-day  afford  to  neglect  the  splendid  material 
that  comparative  psychology  has  succeeded  in  accumulating.  This,  surely, 
is  only  possible  in  the  man  whose  outlook  is  absolutely  restricted  by  animistic 
doctrines  which  belong  to  the  past.  Undoubtedly  one  should  take  by  pre- 
ference those  mammals  in  which  intelligence  is  most  developed,  animals 
in  the  common  life  of  which  we  can,  by  suitable  experiments,  detect  un- 
doubted signs  of  judgment,  memory,  comparison,  emotion  and  new  adapta- 
tions. These  signs  are  derived  from  a  combination  of  mental  processes  of 
remarkable  complexity,  reduction  or  suppression  of  which  can  be  brought 
about  by  means  of  localised  cerebral  destructions. 

Kalischer,3  in  particular,  has  expressed  grave  doubts  as  to  the  applica- 
bility of  the  results  of  experiments  upon  animals,  more  especially  dogs, 
to  the  psychic  functions  of  the  human  brain.  He  is  seconded  by  Roncoroni,4 

1  Dejerine.     Anatomic  des  centres  nerveux.     Vol.  ii.     1909. 

2  Bianchi  jun.     "  Alterazioni  istologiche  della  corteccia  cerebrale  in  seguito  a 
focolai  distruttivi  ed  a  lesioni  sperimentali.     Ann.  di  Nev.     1912. 

3  Kalischer.      "  Zur  Function  des  Schliifenlappens  des  Grosshirns.     Experimen- 
telle  Physiologie  des  Grosshirns."     Handbuch  der  Neurologie.     Teil  1. 

4  Roncoroni.    "  Le  Funzioni  dei  lobi  prefrontali  in  rapporto  ai  dati  architettonici." 
Rivista  di  Patologia  nervosa  e  mentale.     1911. 


128  THE  MECHANISM  OF  THE  BRAIN 

who  also  expresses  the  view  that  one  has  to  be  very  careful  in  drawing 
deductions  from  experiments  on  animals  and  applying  these  to  mental 
conditions  in  man.  The  warning  is  justified,  but  one  cannot  agree  with 
Kalischer  when  he  asserts  that  the  whole  cerebral  cortex  of  the  dog  can  be 
removed  without  the  animal  showing  any  fundamental  alterations  in  its 
behaviour.  One  has  to  admit  that  the  psychological  analysis  of  animals 
is  a  very  difficult  matter.  Kalischer's  views  certainly  contrast  with  those 
of  Munk  and  Goltz,  both  of  whom  expressed  a  very  different  opinion. 

Many,  if  not  the  greater  number  of,  experiments  that  have  been  directed 
towards  the  investigation  of  the  functions  of  the  frontal  lobes,  have  been 
made  upon  dogs  and  cats.  Many  too  have  been  made  on  monkeys,  and 
some  on  rabbits.  Now  it  is  evident  that  the  only  mammal  which  lends 
itself  advantageously  to  the  investigation  of  the  frontal  lobes  is  the  monkey. 
Experiments  carried  out  on  dogs  and  cats  also  give  promise  of  fairly  useful 
results,  as  has  been  shown  by  those  performed  in  the  laboratories  of 
Bechterew,  Shepherd  and  the  author.  They  serve  the  more  delicate  purposes 
of  control,  and  in  any  case,  should  be  included  in  the  series  of  experiments 
of  any  investigator  who  sets  out  to  inquire  into  the  function  of  the  frontal 
lobes. 

Intelligence  and  emotions  with  their  relative  associative  mechanisms  are 
markedly  developed  in  dogs. 

Pavlov1  and  some  of  his  pupils  succeeded  in  establishing  the  existence 
of  associations  between  the  fundamental  sensations  by  examining  the  salivary 
secretion.  A  gustatory  stimulus  such  as  meat  powder  placed  on  the  animal's 
tongue,  after  a  fistulous  opening  into  Stenson's  duct  has  been  made,  deter- 
mines a  marked  increase  of  the  salivary  secretion.  If,  after  a  number  of 
educative  experiments  of  this  kind  have  been  made,  the  animal  is  allowed 
to  see  the  same  substance  at  a  distance,  a  like  increase  of  salivary  secretion 
generally,  though  not  invariably,  occurs.  In  these  cases  an  association  is 
formed  between  the  tacto-gustatory  cortical  centres  and  the  visual  centre, 
excitation  of  which  by  the  sight  of  the  meat  brings  about  the  cortico-gustatory 
salivary  reflex.  Subbok's  experiments  also  are  well  known.  This  in- 
vestigator wrote  words  upon  sheets  of  paper  and  trained  his  dog  to  recognise 
these  by  the  spoken  word.  The  dog,  as  a  rule,  obeyed  the  command  and 
selected,  from  amongst  the  papers,  that  on  which  was  written  the  word 
pronounced  by  his  master.  One  need  only  be  reminded  of  the  extent  to 
which  dogs  can  be  trained  for  public  exhibition  and  how  they  understand 
a  number  of  words  corresponding  to  determined  actions  performed  by  them. 

Zeliony,2  using  the  method  introduced  by  Pavlov,  carried  out  numerous 
and  patient  experiments  in  dogs  and  demonstrated  associations  between 
meat  powder  placed  upon  the  tongue  and  acoustic  stimulations  (harmonium, 
trumpet,  etc.).  Having  made  a  fistulous  opening  into  Stenson's  duct,  the 
drops  of  saliva  were  allowed  to  fall  upon  a  small  gutter  with  a  registering 
lever,  from  which  they  ran  into  a  graduated  vessel,  so  that  he  was  able  to 

1  Pavlov.     Atti  del  Congresso  di  Madrid.     1904. 

2  Zeliony.     Archives  des  Sciences  Biologiques.     1909  (referred  to  by  Bohn). 


METHODS  OF  INQUIRY  129 

register  the  number  of  drops  that  fell  into  the  gutter  and  to  measure  exactly 
the  quantity  of  saliva  obtained.  As  in  the  case  of  the  visual  stimuli,  associa- 
tions were  found  to  have  been  formed  between  the  acoustic  excitation  and 
the  reflex  salivary  secretion  when  various  instruments  were  used.  Without 
discussing  these  experiments  in  detail  it  can  be  definitely  stated  that  new 
associations  can  be  developed  by  means  of  education.  Dogs,  and  to  a  greater 
extent,  monkeys,  can  form  many  new  visual  images  of  form,  colour  and 
distance,  as  well  as  auditory  and  musical  images,  variously  associated  with 
one  another  and  capable  of  giving  rise  to  reflexes  or  motor  orientations  or 
to  inhibitions.  At  the  same  time  it  is  to  be  remarked  that,  so  far  as  concerns 
the  function  of  the  frontal  lobes,  experiments  on  dogs  do  not  in  themselves 
furnish  legitimate  bases  for  conclusions,  because  the  frontal  lobe  in  these 
animals  is  still  poorly  developed.  Further,  it  is,  as  we  have  seen,  so  near 
to  the  anterior  branch  of  the  sigmoid  gyms  that  even  limited  extirpations 
can  hardly  ever  be  carried  out  in  it  without  at  the  same  time  doing  injury 
to  that  branch,  where  there  are  also  motor  centres.  Thus  it  happens  that, 
if  the  lesion  is  exceedingly  limited,  either  no  conspicuous  mental  disturbances 
are  observed,  or,  on  the  other  hand,  these,  when  they  occur,  are  complicated 
by  motor  and  sensory  disorders,  in  which  case  no  legitimate  conclusion 
can  be  drawn. 

Besides  doing  injury  to  the -motor  zone,  especially  that  pa,rt  concerned 
in  the  musculature  of  the  trunk  and  neck  (which  in  dogs  is  prolonged  fairly 
far  forward,  although  it  does  not  involve  the  entire  extent  of  the  frontal 
lobe,  as  Munk  maintained),  one  is  liable  to  do  damage  to  the  olfactory  bulb, 
which  is  very  close  to,  or  in  actual  contact  with,  the  frontal  lobe.  In  all  his 
experiments  the  writer  made  it  a  rule  not  to  injure  any  motor  or  sensory 
centre  or  any  sensory  path,  because,  if  the  animal  becomes  deprived  of  a 
series  of  perceptions  of  the  external  world  (especially  olfactory  perceptions 
in  the  dog),  the  psycho-reactive  function  is  disturbed  or  reduced,  and  one  is 
apt  to  put  down  any  disturbance  in  the  mental  behaviour  of  the  animal  to 
destruction  of  the  frontal  lobe,  whereas  in  reality  it  depends  upon  destruction 
of  a  sensory  centre  or  its  projection  paths. 

The  wide  gulf  that  appears  to  separate  man  from  other  mammals  is  being 
gradually  narrowed  as  the  result  of  incessant  research.  The  writer  cannot 
here  enter  upon  any  discussion  of  Darwin's  doctrine  of  descent,  or  the  relative 
views  of  any  other  writer  such  as  G.  Bohn,  who  maintained  that  man  appeared 
upon  the  earth  by  abrupt  mutations  and  was  a  species  of  large-brained 
monster  who,  with  the  aid  of  intelligence,  dominated  the  animal  world 
surrounding  him.  At  the  same  time  one  has  to  admit  from  what  has  already 
been  accomplished  that  psychological  investigations  are  full  of  promise. 

Thorndike,1  in  an  experimental  study  of  the  associative  processes  in 
platyrrhines,  which  are  not  the  most  intelligent  of  monkeys,  proved  that 
these  quadrumanes  were  capable  of  acquiring  new  adaptations  when  placed 
under  entirely  new  circumstances.  As  compared  with  other  animals  the 

1  Thorndike.     "  Animal  Intelligence  :  an  Experimental  Study  of  the  Associative 
Processes  in  Animals."     Suppl.  to  Psychological  Review.      1908. 
I 


130  THE  MECHANISM  OF  THE  BRAIN 

associations  were  more  rapid,  more  numerous  and  complex,  and,  at  the 
same  time,  there  was  a  greater  perceptive  fineness  and  a  higher  capacity  of 
attention  and  memory,  which  enabled  these  animals  to  turn  to  account  all 
that  they  had  learned.  The  present  writer,  as  the  result  of  his  studies  of 
many  individual  monkeys  as  well  as  small  tribes  of  cebidse,  was  able  to 
confirm  this  verdict  as  to  the  monkey's  intelligence.  These  animals  ex- 
hibited a  much  higher  perceptive  capacity  than  the  dog,  rapid  judgment, 
fairly  extensive  associations,  a  good  use  of  memory,  educability,  and  a 
capacity  for  forming  new  adaptations  when  placed  under  strange  conditions. 
An  account  of  these  observations  is  given  in  the  following  chapter. 

It  has  been  said  that  chimpanzees  do  not  distinguish  colours.  The 
researches  of  Thorndike,  Jennings  and  Kinnaman  have  proven  that  even 
the  lower  monkeys — such  as  Macacus  Rhesus  upon  which  Kinnaman  experi- 
mented— perceive  at  a  distance  the  form  of  an  object,  its  size,  its  colour, 
and  its  spatial  relations.  The  animal  is  capable  of  making  a  selection  from 
amongst  several  objects,  and  in  the  various  phases  of  its  conduct  it  is  not 
difficult  to  detect  motives  for  its  actions,  for  these  are  based  on  precise 
perceptions  and  on  tests  which  evidently  have  for  their  purpose  the  avoidance 
of  errors.  Bohn  would  recognise  in  all  these  the  elements  of  a  superior 


consciousness. 


The  experiments  detailed  in  the  following  chapter  furnish  confirmatory 
evidence  of  precise  perceptions,  judgments,  comparisons,  of  memory  with 
trials  and  tests,  and  of  new  adaptations.  Cebidse  certainly  distinguish  yellow 
from  green  and  red  from  blue.  I  have  never  been  able  to  detect  in  cebidce 
kinocephalidw  any  articulation  of  syllabic  sounds,  although  I  have  observed 
many  inflexions  of  vocal  sounds,  along  with  some  mumbling,  in  the  course  of 
their  erotic  manifestations,  and  movements  of  the  lips  suggestive  of  the  kiss. 
Gamier,  as  recorded  by  Ingenieros,2  under  very  special  conditions  in  the 
virgin  forests  of  tropical  Africa,  was  able  to  detect  a  certain  number  of 
articulate  sounds.  Apart  from  this  finding,  which  the  author  had  no  means 
of  confirming,  there  are  vocal  inflexions  expressing  various  emotional  states, 
which  are  rather  more  numerous  in  the  cebus  than  in  the  dog. 

It  is  not  within  the  scope  of  this  volume  to  attempt  to  trace  a  parallelism 
between  the  mental  life  of  various  species  of  animals  and  that  of  the  human 
being  in  his  successive  phases  of  development.  The  author  trusts  that  it 
will  not  be  said  of  him  that  he  has  been  caught  in  the  net  of  anthropo- 
morphism, but  he  is  compelled  to  admit  that  in  the  more  intelligent  monkeys 
one  can  even  perceive  the  rudiments  of  human  sociability — i.e.  of  love,  friend- 
ship, protection,  maternal  sentiment,  feeling  of  injured  dignity,  jealousy  and 
ridicule. 

Shepherd,  following  Hitzig's  example,  has  studied  the  symptoms  resulting 
from  mutilation  of  the  frontal  lobes  in  trained  monkeys  such  as  those  taken 
about  by  showmen.  The  writer  also  at  first  preferred  trained  monkeys  for 
his  experiments,  and  certainly  the  symptoms  that  resulted  from  extirpation 

1  Bohn.     La  Naissance  de  V Intelligence.     1907. 

2  Ingenieros.     Principios  di  Psicologia  Biologica.     Madrid,  1913, 


METHODS  OF  INQUIRY  131 

of  the  frontal  lobes  were  very  impressive.  The  loss  of  what  is  a  product  of 
education,  however,  may  be  a  source  of  error,  in  view  of  the  following  facts. 
In  all  the  severe  and  diffuse  encephalopathies  in  the  human  subject,  what 
is  most  certainly  lost  is  the  product  of  education ;  further,  all  dementias 
consecutive  to  psychopathies  which  do  not  depend  very  largely  upon 
diseases  of  the  frontal  lobes,  and  consecutive  to  diffuse  degeneration  or  in- 
flammatory processes,  are  contra-distinguished  by  the  loss  of  the  most  recent 
acquisitions.  Hence,  the  writer  has  considered  it  preferable  to  experiment 
upon  monkeys  brought  in  their  savage  state  from  the  Red  Sea  littoral.  He  has 
subjected  these  monkeys  first  of  all  to  an  accurate  psycho-somatic  examina- 
tion, investigating,  one  by  one,  all  the  senses,  the  rapidity  and  mode  of  per- 
ceiving and  reacting,  the  habits,  the  emotions,  the  affections,  as  well  as  new 
attitudes  and  adaptations,  so  as  to  be  able  to  formulate  a  sort  of  psychic  equa- 
tion for  each  animal.  By  adopting  this  method  one  was  in  a  better  position 
to  estimate  the  loss  of  mental  capacity  in  each  animal  after  the  mutilation. 

To  detect,  measure  and  appraise  the  changes  and  the  reduction  in 
cerebral  action  caused  by  the  mutilation  is  indeed  the  most  difficult  part  of 
the  experiment.  At  the  International  Congress  in  Rome  in  1894,  the 
Committee  appointed  for  the  purpose  of  pronouncing  judgment  as  to  the 
mental  condition  of  the  mutilated  monkey  which  the  writer  presented  before 
it  was  impressed  by  the  fact  that  the  animal  recognised  objects  and  executed 
adequate  movements  of  prehension  like  other  members  of  the  same  family. 
Its  behaviour  seemed  to  be  quite  in  keeping  with  the  normal  mentality  of 
these  quadrumanes.  Indeed,  it  exhibited  abundant  evidence  of  perceptive 
capacity  and  of  coherence  in  action. 

As  a  matter  of  fact  the  animal  operated  upon  sees  objects,  recognises 
them,  shows  emotional  activities  (desire  and  sometimes  repulsion)  and 
executes  appropriate  movements. 

The  writer  has  no  hesitation  in  saying  that,  in  some  cases,  he  has  found 
himself  in  a  difficulty  very  similar  to  that  in  which  the  alienist  finds  himself 
when  he  is  called  upon  to  express  an  opinion  as  to  the  civil  and  juridical 
capacity  of  a  man  in  a  condition  of  slight  imbecility. 

There  can  be  no  question  as  to  the  fallacy  involved  in  the  method  adopted 
by  some  investigators,  that  of  examining,  merely  en  passant,  the  monkeys 
operated  upon,  throwing  to  them  a  sweet,  a  coin,  a  fruit,  and  then  judging 
that  their  behaviour  differed  in  no  way  from  the  normal  inasmuch  as  they 
perceived,  picked  up  and  made  use  of,  these  objects.  When  one  thinks  of 
the  time  that  is  required  in  order  to  define  the  mental  capacity  of  a  monkey 
before  as  well  as  after  mutilation,  or  of  a  human  imbecile,  one  cannot  help 
feeling  surprised  that  anyone  should  venture,  after  five  minutes,  to  express 
an  opinion  upon  the  mental  condition  of  a  monkey  that  has  suffered  mutila- 
tion of  the  .frontal  lobes,  without  first  starting  out  from  a  comparative 
examination,  which  in  every  case  requires  method  and  time. 

With  regard  to  the  question  how  far  the  motor  zone  extends  in  front, 
more  especially  that  part  of  it  concerned  in  the  movements  of  the  neck  and 


132  THE  MECHANISM  OF  THE  BRAIN 

trunk,  there  is  a  lack  of  agreement.  Independently  of  his  own  observations 
the  author  is  convinced,  from  examination  of  the  facts  adduced,  and  the 
methods  employed,  by  different  authorities,  that  the  difference  in  opinion 
depends,  in  part  at  least,  upon  individual  differences  and  on  diversity  of 
the  methods  followed.  How  otherwise  can  one  explain  the  fact  that  observers 
like  Hitzig,  Munk,  Ferrier,  Horsley,  Schafer  and  Luciani  located  the  centres 
for  the  muscles  of  the  neck,  head  and  trunk  of  dogs  and  monkeys  in  points 
of  the  brain  that  do  not  at  all  coincide  ?  How  are  we  to  explain  the  fact 


Fig.  50 
(after  Ferrier) 

1,  2,  3.  Areas  for  movements  of  the  lower  limb  and  tail.— 
4  (a,  b,  c,  (1),  5,  0.  Areas  for  the  various  segments  of  the 
upper  limb.— 7,  8,  11.  Areas  for  movements  of  face  and 
tongue.— 12.  Area  for  opening  of  eyelids,  dilatation  of 
pupil,  and  movements  of  head  and  eyes  to  the  opposite 
side.— 13.  Movements  of  the  eyes  (angular  gyrus— 
visual  area). — The  area  for  movements  of  the  ear  is  on 
external  aspect,  below  13 

that  Munk,  Glosglik  and  others  have  also  maintained  in  later  works  that,  in 
dogs,  the  frontal  lobes  in  front  of  the  sigmoid  gyrus  are  nothing  else  than 
sensory  and  motor  centres  for  the  muscles  of  the  neck  and  trunk,  forming 
a  part,  i.e. ,  of  the  Fuhlsphare  ?  An  examination  of  their  respective  works 
shows  that  Munk  and  others  have  employed  very  strong  currents,  and  that 
the  extirpation  was  effected  at  a  point  rather  far  back  in  the  frontal  lobe, 
so  that  electric  excitation  gave  rise  to  muscular  contractions,  and  extirpation 
to  paralysis  or  paresis  of  the  muscles  of  the  neck  and  trunk  and  also  to 
sensory  disturbances,  facts  which  the  author  frequently  confirmed  in  his 
control  experiments  upon  dogs  and  monkeys. 

The  difference  in  situation  between  the  area  for  the  movements  of  the 
head  and  trunk  denned  by  Ferrier  (area  12,  Fig.  50)  and  that  defined  by  the 
writer  can  only  be  explained  by  the  greater  strength  of  the  currents  used  by 
Ferrier,  who  is  nevertheless  one  of  the  most  experienced  investigators.  If  a 
small  area  of  the  posterior  part  of  the  frontal  cortex  of  the  monkey  be  laid 


METHODS  OF  INQUIRY  133 

bare  and  then  strongly  excited,  movements  of  the  head  and  eyes  are  pro- 
voked. If,  without  displacing  the  electrodes,  weaker  currents  are  used  we 
get  movements  only  of  the  eyes.  If  the  strength  of  the  current  is  again- 
increased  the  movements  of  the  head  again  appear  upon  the  scene,  without 
any  displacement  of  the  electrodes.  An  argument  that  is  sometimes  brought 
forward  in  favour  of  Munk's  thesis  is  this,  that,  whilst  these  fairly  strong 
excitations  of  the  frontal  zone  provoke  movements  of  the  head,  they  do  not 
give  rise  to  movements  of  the  upper  limb,  although  the  centre  of  the  upper 
limb  is  in  closer  proximity  to  the  point  excited  (as,  e.g.,  when  the  frontal 
centre  for  movements  of  the  ear  is  stimulated) . 

The  reason  for  this  will  be  evident  if  we  take  into  consideration  the 
synchronicity  of  the  movements  of  the  functional  association,  and  reflect 
that  the  centre  for  movements  of  the  head  must  be  closely  connected  by 
means  of  associative  fibres  with  the  frontal  centres  for  the  eyes  and  ears. 
In  attentive  states  in  dogs,  especially  hunting  dogs,  but  even  more  par- 
ticularly in  monkeys,  which  are  suspicious,  alert  and  cautious,  the  move- 
ments of  the  eyes,  ears  and  head  form  one  inseparable  whole,  taken  along 
with  that  particular  psychic  state  which  we  would  describe  as  attentive  and 
observant  (suspicious  and  expectant  attention).  If  there  are  numerous 
associative  paths  it  is  easy  to  understand  that  the  waves  of  electric  excitation 
may  be  transmitted  along  these  to  points  somewhat  more  distant,  like  those 
concerned  with  the  head  and  eyes,  whilst  there  may  be  difficulty  in  provoking 
movements  of  the  upper  limb  (although  the  areas  concerned  with  the  latter 
are  nearer  to  the  point  of  excitation)  because  associations  between  the  area 
of  the  limbs  and  the  frontal  zone  are  not  so  often  called  into  play  and  con- 
sequently not  so  well  established.  This  is  confirmed  by  the  fact  that  in 
states  of  attention  the  limbs  take  no  part  in  the  particular  movements  of 
the  eyes,  head  and  ears,  but  rather  are  inhibited. 

The  intensity  of  the  current  must  be  measured  on  a  sledge  by  an  assistant, 
and  estimated  by  the  experimenter  by  means  of  the  effects  produced,  in 
the  same  way  as  we  test  the  electric  excitability  of  a  muscle  which  we  suppose 
to  be  affected  by  atrophy  with  degeneration.  We  apply  a  small  electrode, 
with  a  hand  interrupter,  to  the  point  of  excitation  of  the  muscle,  and  move 
along  the  sledge  regulator  until  we  notice  the  first — i.e.  the  weakest — con- 
traction, and  from  this,  after  due  control,  we  judge  as  to  the  state  of  the 
muscle.  No  clinical  neurologist  would  commit  the  error  of  employing  strong 
currents  when  he  wishes  to  learn  the  state  of  individual  muscles  or  nerves. 
It  is  necessary  to  proceed  in  a  similar  manner  when  we  seek  to  test  the 
excitability  of  the  various  points  of  the  cerebral  cortex. 

Some  remarks  are  due  as  to  the  extent  of  the  field  of  operation.  At 
the  International  Congress  of  Psychology  in  Rome,  Sciamanna,1  who  reported 
upon  the  effects  of  removal  of  the  frontal  lobes,  believed  he  had  extirpated 
the  frontal  lobe,  whilst,  as  a  matter  of  fact,  he  had  succeeded  in  excising 
only  a  small  portion  of  it.  It  is  well  that  we  should  be  clear  upon  this  point. 

1  Sciamanna.     Loc.  cit. 


134 


THE  MECHANISM  OF  THE  BRAIN 


The  frontal  field  of  experiment  comprises  that  portion  of  the  brain  which 
lies  in  front  of  the  convolution  of  Rolando  and  includes  a  part  of  the 
intermediate  motor  area. 

In  the  author's  experiments  there  was  destroyed  or  isolated  not  only 

C.RA 


S.CR 


C.F.S 


SP.RF 


Fig.  51. — Brain  of  cebus 

SPRF.  Pre-frontal  sulcus.— CFS.  .Superior  frontal  convolution.— CRA.  Anterior   Rolandic  con- 
volution.— SCR   Rolandic  fissure. — SS.  Fissure  of  Sylvius. — TS.  Superior  temporal  convolution 


r 


Fig.  52. — Vertical  section  through  the  frontal  area 
showing  softening  of  the  white  substance  of  the 
frontal  lobe  of  cebus,  which  is  arrested  in  front 
of  the  motor  area 

the  pre-frontal  area,  but  also  the  frontal  and  sometimes  a  part  of  the  inter- 
mediate zone.  In  most  instances  the  excitable  part  of  the  frontal  zone, 
indicated  by  the  numbers  1,  2,  3,  4,  5,  Figure  51,  was  included  in  the  field 
of  extirpation. 

The  experimental  inquiries  thus  far  completed  go  to  establish  a  relation 


METHODS  OF  INQUIRY  135 

between  the  effects  and  the  extent  of  the  mutilation.  Very  limited  extirpa- 
tions of  the  frontal  lobe,  even  when  bilateral,  do  not  produce  appreciable 
effects.  It  is  to  be  added  that  in  few  cases  did  the  writer  succeed  in  excising 
all  the  external  surface  of  the  frontal  lobe.  Very  often  there  remained  some 


Fig.  53. — Frontal  lobes  separated  from  the  motor  area  with 
the  exception  of  the  operculum,  and  le 


Fig.  54. — Decortication  of  frontal  lobe,  left  in  situ 

small  bridge,  either  of  the  superior  frontal  convolution  or  of  the  opercular 
part  of  the  frontal  zone. 

The  author  has  hardly  ever  removed  the  orbital  surface,  which  also  forms 
a  part  of  the  frontal  lobe.  This  is  another  field  for  experiment  and  has 
scarcely  been  explored. 

The  figures  here  reproduced  (Figs.  51,  52,  53,  54,  55)  are  serial  sections 


136 


THE  MECHANISM  OF  THE  BRAIN 


showing  the  extent  of  mutilation  or  decortication,  and  also  the  parts  of  the 
frontal  lobes  that  were  spared. 

The  electrically  excitable  frontal  zone  forms  a  part,  along  with  the  pre- 
frontal  area,  properly  so  called,  of  the  whole  area,  excision  of  which  does  not 
give  rise  to  any  sensory  or  motor  disturbance,  and  must  be  included  for  the 
present  in  the  study  of  the  functions  of  the  frontal  lobe,  for  reasons  which 
will  be  explained  further  on.  The  constant  experience  has  been  that  excision 


Fig.  55. — Section  through  the  posterior  limit  of  the  ex- 
perimental lesion  in  front  of  the  motor  area.  The 
orbital  surface  and,  on  one  side,  the  operculum,  are 
spared 

of  one  frontal  lobe  alone  does  not  produce  appreciable  effect.  It  is  only 
when  a  large  part  of  the  left  frontal  lobe  is  extirpated  that  the  effects  are 
perceptible.  All  objections  based  upon  methods  that  are  not  really  suited 
to  furnish  proofs  of  the  function  of  the  frontal  lobes  ought  to  be  put  to  one 
side. 

These  preliminary  considerations  prepare  the  way  for  the  following 
summary  of  experiments  upon  dogs  and  monkeys,  some  of  which  have  not 
previously  been  published. 

It  is  superfluous  to  add  that  in  his  researches  the  writer  paid  the  strictest 
attention  to  aseptic  methods,  and  for  excitation  of  the  brain  used  small 
bipolar  electrodes  with  a  hand  interrupter,  the  electrodes  being  formed 
of  two  little  shafts  of  platinum  with  clubbed  points,  a  little  less  than  one 
millimetre  in  diameter,  and  two  or  three  millimetres  apart  from  one  another. 
A  good  sledge  of  the  Du  Bois  Reymond  type  permitted  sufficient  accuracy 
in  the  measurement  of  the  faradic  current  employed  in  the  excitation  of  the 
various  points  of  the  cortex. 


CHAPTER  V 

Clinical  and  Experimental  Histories  of  Dogs,  Foxes 
and  Monkeys,  including  Controls 

EXPERIMENT  1. — llth  June  1889. — An  adult  dog,  alert,  healthy,  docile.  Ex- 
amination prior  to  operation  showed  perfect  integrity  not  only  of  motility  but  also 
of  all  kinds  of  sensibility.  It  was  intelligent,  obedient,  quiet,  affectionate. 
Anaesthesia  with  morphine  and  chloroform.  Skull  opened  with  trephine,  of  about 
2  cm.  diameter,  in  occipital  region  on  both  sides,  1  cm.  in  front  of  the  occipital 
protuberance  and  -^  cm.  from  the  median  line  on  each  side,  leaving  a  bridge  of  about 
1  cm.  between  the  two  openings.  Moderate  haemorrhage.  Exposed  the  upper  part 
of  the  second  external  bifurcated  convolution  and  a  portion  of  the  first.  Removed 
neatly  the  exposed  cortical  disc  after  making  a  circular  incision  into  the  cortex, 
with  the  bistoury  following  the  edge  of  the  opening.  Destroyed  and  removed 
another  part  of  the  cortex  on  both  sides  by  slightly  extending  the  lines  outwards 
and  posteriorly.  Arrest  of  haemorrhage  followed  by  lavage  of  the  surface,  asepsis, 
suture  of  the  dura  mater  and  of  the  soft  tissues,  and  antiseptic  dressing. 

14th  June  1889. — Three  days  later  the  dog  was  found  seated  on  his  hind  quarters 
quite  alert,  with  head  raised  and  eyes  open  and  turned  towards  the  door.  The  ears 
were  raised  in  the  attitude  of  attention.  A  second  dog,  previously  operated  upon, 
was  allowed  to  enter  the  room.  It  barked.  Dog  No.  1  rose,  darted  forward  in  the 
direction  of  the  new-comer,  turning  to  right  and  left  through  the  sector  of  a  circle 
whose  radius  would  be  represented  by  the  chain  which  confined  him.  He  was  full 
of  strength,  had  his  tail  up-turned,  the  head  erect,  and  the  opened  eyes  fixed  in  the 
void.  On  attempting  to  frighten  him  by  pretending  to  strike  him  with  a  stick  or 
waving  a  hat  to  and  fro  just  in  front  of  him,  he  remained  immobile  till  all  was  quiet, 
when  he  immediately  turned  his  gaze  in  the  direction  of  the  second  dog  and  fixed  it 
in  the  void,  or,  again,  if  the  air  was  agitated,  with  the  hat  or  the  hand  very  close 
to  him,  he  beat  a  retreat,  in  an  attitude  that  suggested  something  between  fear 
and  observant  suspicion. 

The  first  examinations  showed  hearing  and  tactile  sensibility  to  be  very  fine, 
but  he  did  not  see  a  sheet  of  white  paper  placed  in  front  of  his  nose.  Only  on 
touching  the  nose  with  the  paper  did  he  throw  the  head  back  in  an  attitude  of 
surprise,  directing  his  gaze  towards  the  nose. 

He  heard  the  slightest  noises,  moving  the  ears  and  directing  the  gaze  in  the 
direction  of  these.  If  a  vibrating  tuning-fork  was  brought  near  to  any  of  the  ears 
he  became  afraid  and  retreated. 

He  reacted  to  the  lightest  tactile  stimuli,  equally  on  both  sides.  On  drawing 
a  feather  or  a  pencil  lightly  across  the  ears,  back,  nose  or  paws  he  shook  himself 
and  turned  in  the  direction  of  the  stimulus.  He  scratched  himself  wherever  there 
was  any  parasite,  with  equal  readiness  and  strength  on  either  side.  If,  in  a  dark 
room,  a  lamp  was  lit  in  front  of  him,  he  seemed  to  perceive  the  sudden  light.  He 
turned  his  gaze  towards  it  and  the  pupils  reacted. 

He  was  suspicious.  If  one  came  upon  him  unawares  and  touched  him  lightly, 
he  turned  cautiously  away  to  hide  himself  in  a  corner  of  his  bed.  When  taken 
out  into  the  passage,  he  knocked  against  the  walls,  now  to  the  right  and  then  to 
the  left,  then  threaded  his  way  along  the  passage  and  arrived  at  the  exit.  Here, 
however,  as  the  white  of  the  passage  ended,  he  knocked  against  the  wall,  first  on 
137 


138  THE  MECHANISM  OF  THE  BRAIN 

the  right  then  on  the  left,  then,  sniffing  and  calling  to  his  aid  the  sense  of  touch, 
he  felt  his  way  cautiously  and  finally  succeeded  in  passing  through  the  doorway. 
If,  on  the  way,  he  came  to  a  step,  he  put  forward  his  paw  and,  finding  no  resistance, 
he  withdrew  it  again,  as  though  afraid  of  falling  into  space,  then  thrust  forward 
his  nose  and  tried  again  with  his  paw.  If,  in  this  way,  he  became  convinced  of  the 
presence  of  steps  he  then  descended  briskly.  In  a  similar  way  he  succeeded  in 
mounting  the  steps. 

18th  June  1889. — He  was  always  alert,  in  good  humour,  knew  quite  well  the 
voice  of  the  attendant  who  brought  him  food,  ate  well,  and  exhibited  erotic 
tendencies  (he  attempted  to  cover  another  dog  that  had  also  suffered  mutilation 
of  the  frontal  lobes).  The  wound  was  healing  by  first  intention  without  trace  of 
suppuration. 

28th  June  1889.— Healed  by  first  intention.  Mental  condition  identical. 
Sight  was  improved  so  that  he  knocked  less  against  obstacles.  An  unsuccessful 
attempt  was  made  to  measure  the  visual  field.  He  was  always  alert,  sometimes 
full  of  strength  ;  had  marked  erotic  tendencies  ;  well  cared  for,  he  was  kept  alive 
for  several  months  in  the  same  condition. 

18th  January  1890. — On  this  date  epileptic  convulsions  came  on  the  scene  and 
were  repeated  with  Jacksonian  characteristics  (rhythmical  contractions  of  left  side). 
If  one  called  to  him  during  the  attack  he  was  able  to  raise  his  head  languidly. 
For  some  days  he  remained  paretic  on  the  left  side,  then  regained  his  ordinary 
condition  but  was  not  so  alert  nor  so  spirited  as  previously.  He  walked  with  a 
slightly  ataxic  gait,  the  left  anterior  limb  in  particular  being  raised  rather  high 
from  the  ground.  Tactile  sensibility  when  tested  was  found  to  be  normal.  If 
touched  on  the  ear,  the  side  of  the  nose,  or  any  of  the  limbs,  he  always  turned  to 
that  side.  There  was  no  difference  in  this  respect  between  the  two  sides.  There 
was,  however,  diminished  power  in  the  limbs,  more  especially  on  the  left  side,  so 
that  sometimes  his  paws  bent  under  the  weight  of  his  body,  especially  when  making 
any  effort.  Resistance  to  passive  movements  was  diminished.  Smell  was  found, 
when  tested,  to  be  somewhat  diminished.  He  was  kept  fasting  for  about  twenty- 
four  hours  and  then  taken  to  the  observation-room  into  which  a  plate  of  meat 
was  brought.  He  became  quite  animated  again  and  went  sniffing  around.  He 
did  not  always  find  the  place  where  the  plate  lay,  not  recognising  it  until  it  was 
pushed  quite  close  up  to  him  as  he  went  around  so  that  he  knocked  against  it  with 
his  nose,  or  happened  to  touch  a  piece  of  meat,  which  he  seized  in  his  teeth  and 
ate  with  evident  enjoyment.  If  pieces  of  bread  and  meat  were  mixed  together 
and  thrown  in  front  of  him  he  made  no  selection,  but,  nosing  around,  ate  indis- 
criminately whichever  piece  he  first  came  across.  As  a  rule,  when  walking,  he 
avoided  any  objects  or  obstacles  in  his  way,  but  if  he  quickened  his  pace  he  often 
came  against  them  lightly  with  his  nose,  which  he  always  kept  extended  in  front 
of  him  to  aid  him  in  avoiding  them.  Hearing  was  good.  When  called  he  turned 
round,  but  in  most  instances  did  not  guess  correctly  the  direction  whence  came 
the  voice.  If  the  tuning-fork  was  approximated  to  one  of  his  ears  he  shook  himself 
and  retreated  in  surprise  at  the  strange  noise,  the  eyes  remaining  fixed  as  though 
seeking  to  discover  the  cause  of  the  unusual  sensation  ;  this  was  true  of  both  ears. 
It  was  evident,  however,  that  he  still  looked  into  space  just  as  before.  The  pupils 
were  dilated  and  reacted  to  light  but  there  were  no  movements  of  accommodation 
even  when  a  lamp  was  passed  at  various  distances  in  front  of  his  eyes  in  a  dark 
room.  It  seemed,  however,  that  he  was  aware  of  the  light,  because,  if  he  was  taken 
by  surprise,  and  a  ray  of  light  was  allowed  to  penetrate  the  eye  from  any  direction, 
he  showed  evidence  of  fear,  turned  his  head  round  and  hid  it  in  the  arms  holding 
him.  Intelligence,  though  well  preserved,  was  not  what  it  formerly  was.  By 
means  of  his  senses,  other  than  sight,  he  recognised  places,  persons  and  things. 
He  was  very  affectionate  towards  those  who  were  in  the  habit  of  attending  to  him. 
He  was  quiet,  rarely  playful,  often  indifferent,  and  when  left  quietly  to  himself 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     139 

his  attitude  suggested  melancholia,  with  a  distant,  uncertain  look  in  his  eyes  which 
soon  lit  up  again  if  anyone  called  or  fondled  him.  He  had  lost  his  former  vivacity 
and  often  showed  an  extraordinary  fear  of  noises. 

3rd  March  1890. — When  taken  into  the  observation-room  his  condition  was 
found  to  be  unchanged.  For  some  minutes  he  jumped  about  the  room  in  a  joyful 
way,  then  commenced  to  perform  some  movements  as  though  he  saw  a  fly  and 
wished  to  catch  it.  Yet  sometimes,  in  addition,  there  were  movements  of  the  head, 
upwards,  backwards,  and  to  the  left,  movements  of  the  mouth,  which  he  opened 
and  closed  as  though  in  the  act  of  biting  (lateral,  visual  hallucinations  ?).  One 
noted,  too,  spasmodic  movements  of  the  left  orbicularis  palpebrarum  (Jacksonian 
contractions). 

5th  March  1890. — Condition  unchanged.  The  brain  was  exposed  on  the  left 
side  at  a  point  corresponding  to  the  anterior  portion  of  the  second  external  con- 
volution and  a  small  part  of  the  sigmoid  gyrus.  Electric  excitations  in  the  latter 
area  (sigmoid  gyrus)  produced  the  usual  movements  of  the  opposite  limbs,  rather 
exaggerated  and  not  easily  circumscribed,  notwithstanding  the  fact  that  a  very 
slight  intensity  of  current  was  employed.  Electric  stimulation  of  the  exposed  part 
of  the  second  convolution  produced  only  slight  contractions  of  the  orbicularis 
palpebrarum  of  the  opposite  side.  This  part  of  the  cortex  was  then  destroyed, 
the  sigmoid  gyrus  being  spared,  and  the  wound  sutured.  On  examining  the 
animal  next  day  he  was  found  fairly  lively  but  more  unsteady  in  his  gait,  and  he 
made  his  way  through  the  doors  less  easily  than  before.  Circus  movements  towards 
the  left  were  present.  % 

llth  March  1890. — Circus  movements  continued;  they  were  somewhat  more 
marked  than  before,  and  always  towards  the  left.  When  the  right  eye  was  closed 
they  diminished,  and  the  animal  was  able,  to  some  extent,  to  avoid  obstacles. 
On  the  other  hand,  when  the  left  eye  was  closed  he  remained  fixed  in  one  place, 
with  the  head  turned  to  the  left,  and,  when  pushed  to  make  him  walk,  constantly 
knocked  against  things  with  his  right  side — i.e.  on  the  side  of  the  open  eye.  When 
the  left  eye  was  uncovered  he  went  about  the  room  and  followed  those  walking 
therein,  sometimes  mistaking  the  direction  and  at  other  times  knocking  against 
obstacles  (he  was  evidently  unable  to  measure  distances  and  recognise  objects), 
but  when  the  right  eye  only  was  allowed  to  remain  open,  it  was  with  great  difficulty 
he  could  be  induced  to  walk  about,  and  he  was  constantly  knocking  against  things. 

llth  April  1890. — Killed  with  chloroform.  On  post-mortem  examination  the 
brain  seemed  diminished  in  size.  On  the  occipital  lobes  two  cicatrices,  about  the 
size  of  a  two -centimes  coin,  were  observed,  with  retraction  of  the  surrounding  tissue. 
The  first  external  convolution  on  the  right  side,  as  far  as  the  sigmoid  gyrus,  was 
of  a  dirty  whitish  colour,  at  one  point  rather  hard  like  a  cicatrix,  at  another  softened. 
On  the  left  side  the  cicatrix  was  less  retracted,  though  fairly  symmetrical  with  the 
other.  All  the  anterior  part  of  the  occipital  focus  was  more  normal  in  colour, 
and  the  convolutions  in  general  were  better  nourished.  On  the  right  side,  the 
upper  third  of  the  anterior  branch  of  the  sigmoid  gyrus  up  to  the  presylvian  sulcus 
was  softened,  and  there  the  dura  mater  was  adherent.  A  similar  but  much  smaller 
focus  was  found  on  the  left  side,  corresponding  exactly  in  site  to  that  of  the  other 
side.  On  the  inferior  surface,  the  hippocampi  were  symmetrically  diminished  in 
size,  being  reduced  to  two  cysts  of  a  yellowish  white  colour.  The  brain  was 
preserved  in  alcohol. 

llth  April  1890. — A  vertical  section  in  front  of  the  two  cicatrices,  at  a  point 
almost  midway  between  the  presylvian  sulcus  and  the  occipital  extremity,  showed 
marked  dilatation  of  both  lateral  ventricles.  The  caudate  nucleus  is  diminished 
on  each  side.  Below,  the  two  hippocampi  are  transformed  into  two  small  sacs 
occupying  part  of  the  substance  proper  of  these  convolutions. 

The  autopsy  provides  an  explanation :  (1)  of  the  ataxia — the  result  of  the 
lesions  of  the  sigmoid  gyri ;  (2)  of  the  circus  movement  to  the  left — resulting  from 


140  THE  MECHANISM  OF  THE  BRAIN 

the  second  operation  performed  on  the  left  hemisphere ;  (3)  of  the  hyponosmia — 
because  of  the  bilateral  hippocampal  lesions  ;  (4)  of  the  mental  decadence — the 
result  of  the  multiple,  experimental  and  spontaneous,  lesions  and  of  the  secondary 
cerebral  atrophy. 

The  post-mortem  examination  likewise  shows  the  possibility  of  non-experimental 
lesions  in  other  parts  of  the  brain  in  consequence  of  the  primary  experimental 
lesion,  and  the  necessity  of  following  the  animal  with  close  attention,  and  registering 
all  subsequent  and  new  symptomatic  manifestations  that  are  not  to  be  attributed 
to  the  primary  experimental  lesion.  This  case  also  shows  that  although  the  dog  was 
psychically  blind  (it  failed  to  recognise  food  with  the  aid  of  sight,  apart  altogether 
from  the  diminution  of  smell  dependent  on  softening  of  the  hippocampi,  and  apart 
from  the  lesions  of  the  sigmoid  gyri  and  the  spherical  restriction  of  intelligence), 
yet  the  character,  one  might  almost  say  the  personality,  was  recognisable.  In 
particular  the  affective  activities,  the  attention,  the  interest  aroused  by  stimuli 
falling  upon  its  body,  were  fairly  well  preserved. 

EXPERIMENT  2. — A  fairly  young  bitch  ;  sharp,  intelligent,  lively,  obedient, 
good-natured,  educable  ;  for  several  days  past  she  has  been  affectionate  and 
grateful  towards  those  who  had  charge  of  her.  Examination  of  all  forms  of  sensi- 
bility reveals  nothing  abnormal  and  no  difference  can  be  detected  between  the  two 
sides. 

8th  May  1889. — Prepared  for  operation.  Anaesthesia  by  morphine  and  chloro- 
form. .  Section  and  reflection  of  the  left  temporal  muscle  followed  by  trephining 
in  the  temporal  region,  at  a  point  corresponding  to  the  Sylvian  fissure  but  slightly 
above  it.  Enlargement  of  the  opening,  below  and  behind,  with  bone  forceps. 
No  disturbing  incident  during  operation.  Section  of  dura  mater.  Slight 
haemorrhage  arrested  by  ordinary  hsemostasis.  The  third  external  convolution, 
upper  part  of  the  fourth,  and  part  of  the  second,  exposed.  Faradic  excitation 
(with  a  current  hardly  noticeable  on  the  point  of  the  tongue)  in  the  postero- 
superior  area — the  second  external  convolution — produces  dilatation  of  the 
palpebral  fissure  and  of  the  pupil  (previously,  markedly  contracted  by  the  action 
of  the  morphine) ;  further  forwards,  on  the  same  convolution,  stimulation  gives 
no  results  ;  below,  on  the  third  convolution,  it  gives  rise  to  movements  exclusively 
of  the  opposite  ear,  movements  which  continue  in  a  clonic  fashion  even  after  the 
current  is  withdrawn,  and  which  spread  to  the  ocular  bulbs,  the  face  and  the 
limbs,  causing  a  classic  epileptic  convulsion.  This  having  ceased,  the  exposed  part 
of  the  third  convolution,  the  lower  margin  of  the  second,  and  the  exposed  upper 
margin  of  the  fourth  are  removed.  Haemorrhage,  which  is  fairly  profuse,  is 
controlled  ;  lavage  with  sterilised  water  ;  suture  of  dura  mater. 

9th  May  1889. — The  bitch  is  slightly  depressed;  she  is  lying  stretched  out  on 
her  couch,  but  raises  her  head  on  hearing  the  noise  of  the  opening  door,  looks 
round,  and  wags  her  tail.  When  called,  she  turns  her  head  in  the  direction  of  the 
voice  but  does  not  move  from  her  position.  When  lifted  and  placed  in  the  middle 
of  the  room  she  returns  to  her  couch,  walking  well.  Taken  to  a  path  in  the  garden 
she  moves  around,  here  and  there,  in  an  aimless  fashion,  leans  her  head  on  the 
hedge  on  the  right-hand  side  but  does  not  lose  the  path.  She  walks  at  a  good  pace, 
only  occasionally  knocking  against  things  and  always  on  the  right  side. 

20th  May  1889. — After  some  suppuration,  which  commenced  on  the  fourth  day, 
with  a  discharge  from  the  wound,  the  bitch  is  gradually  reviving,  is  putting  on 
flesh  and  regaining  strength.  She  likes  to  lie  stretched  out  on  her  couch.  If 
called,  she  comes  slowly  towards  the  person  calling  her,  wagging  her  tail  as  usual, 
or,  on  the  other  hand,  she  shows  a  good  deal  of  fear  and  walks  in  an  almost  crouching 
fashion.  Left  to  herself  in  the  garden,  she  returns  to  her  couch.  When  carried 
to  some  distance  in  the  garden  and  put  down  where  the  paths  intersect,  she  stops  a 
little,  as  though  to  regain  her  bearings,  then  threads  her  way  along  the  path  which 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     141 

leads  directly  to  her  kennel.  On  the  first  occasion,  when  she  finds  herself  in  front 
of  steps  down  which  she  ought  to  go,  she  turns  to  the  left  (the  side  on  which  she  sees), 
proceeds  for  some  distance,  stops,  turns  round,  retraces  her  steps,  comes  to  the  stair, 
descends,  and  walks  straight  on.  On  the  second  occasion,  instead  of  going  straight 
on,  she  again  turns  to  the  left,  but,  as  before,  turns  back  and  goes  down  the  steps 
in  order  to  reach  her  kennel.  She  does  not  show  her  former  vivacity,  but  some- 
times, squatting  on  her  hind  limbs,  she  makes  some  movements  as  though  to  catch 
flies,  but  this  she  does  only  towards  the  left  side  and  never  towards  the  right  (uni- 
lateral visual  hallucinations  ?).  Sight,  examined  by  the  method  usually  adopted 
in  the  Institute  (application  of  a  vulcanite  eye -shade  under  the  eyelids),  seems 
abolished  in  the  right  eye  ;  the  bitch  does  not  react  to  any  luminous  stimulus  falling 
on  the  right  eye  ;  not  even  from  the  internal  angle  of  the  eye  does  she  appear  to 
perceive  a  light  brought  close  up  to  her,  as  was  often  observed  in  other  dogs.  There 
is  a  central  corneal  ulcer  on  the  left  eye,  with  superficial  epithelial  exfoliation.  The 
visual  field  of  the  left  eye,  apart  from  the  defect  arising  from  the  corneal  spot, 
seems  normal ;  it  presents  none  of  the  signs  of  bilateral  hemianopsia.  The  bitch 
does  not  react  to  the  tuning-fork  brought  close  up  to  the  right  ear  as  she  does  when 
it  is  approximated  to  the  left  ear,  in  which  case  she  lowers  her  head  as  though 
afraid,  and  shakes  her  ears.  There  is  no  noticeable  disturbance  of  sensibility.  She 
reacts  to  punctures  equally  well  on  either  side,  but  if  light  contacts  be  made  on  the 
nose  with  a  piece  of  paper  or  the  head  of  a  pin,  now  on  the  right,  now  on  the  left, 
she  is  seen  to  react  more  briskly  on  the  left  than  on  the  right  side. 
There  is  no  disturbance  of  motion. 

3rd  June  1889. — On  entering  we  find  her  on  her  couch,  seated  on  her  hind 
quarters  in  an  attitude  of  attention.  She  has  lost  some  of  her  former  liveliness. 
She  recognises  the  persons  who  have  had  charge  of  her.  Taken  out  on  to  the  garden 
paths  she  makes  her  way  back  to  the  old  outhouse,  goes  round  it  one  way,  then  the 
other,  then  again  in  an  opposite  direction,  as  though  looking  for  the  door.  She 
raises  the  right  paws  rather  higher  than  the  left.  She  knocks  her  nose  against  the 
wall  on  her  right.  She  persuades  herself  it  is  not  the  door,  takes  the  path  leading 
to  a  kennel  which  is  not  the  one  assigned  to  her,  and  here  accommodates  herself. 
Within  the  kennel,  which  is  rather  spacious,  she  walks  cautiously  about,  as  though 
looking  for  a  place  which  will  suit  her  best.  On  waving  a  piece  of  paper  close  up 
to  her  right  eye,  she  behaves  as  though  nothing  were  there.  On  doing  the  same 
before  the  left  eye  she  gets  angry,  snarls,  shows  her  teeth,  and  tries  to  bite.  Her 
behaviour  is  similar  if  the  other  dog  is  brought  near  her.  She  appears  not  to  form 
an  image  of  what  is  before  her  at  first  sight.  It  is  noticeable,  however,  that  her 
character  is  decidedly  altered.  She  likes  to  remain  at  peace,  is  melancholic  and 
irascible,  preferring  solitude  and  rest. 

She  continues  to  be  decidedly  deaf  in  the  right  ear.  On  testing  sensibility  again 
it  is  found  to  be  normal  on  both  sides. 

2lst  June  1889. — Her  condition  is  precisely  the  same  as  last  recorded.  She 
prefers  solitude,  quiet  and  repose.  She  does  not  move  from  her  bed,  seems  melan- 
cholic and  does  not  come  out,  even  when  called,  so  that  from  time  to  time  it  is 
necessary  to  remove  her  forcibly  from  her  couch  in  order  to  examine  her  (an  abscess 
with  induration  of  the  vulva  is  present  and  may  possibly  be  accountable  for  this 
state).  She  walks  well  and  returns  to  her  couch  from  any  quarter,  showing  neither 
error  nor  uncertainty  in  direction. 

3rd  July  1889. — Suitably  treated,  the  vulvar  abscess  is  cured.  The  cornea, 
rendered  turbid  by  the  ophthalmia,  is  now  quite  clear,  except  for  a  slight  opacity 
in  a  small  central  point.  Taken  out  and  left  to  herself  on  the  garden  paths,  she 
walks  or  runs  back  to  her  couch.  On  the  way  she  knocks  against  the  hedges  on 
the  right  from  time  to  time,  but  much  less  frequently  than  before.  On  again 
covering  the  left  eye  with  the  vulcanite  eye-shade,  she  does  not  wink  when  an 
object  is  passed  rapidly  in  front  of  her  eyelids.  If,  however,  the  room  is  almost 


142  THE  MECHANISM  OF  THE  BRAIN 

dark  and  a  small  lamp  is  lit  in  front  of  her  right  eye  she  is  surprised  by  the  light 
and  draws  back  her  head. 

She  has  had  nothing  to  eat  since  last  night  so  we  make  the  following  experiment. 
While  she  is  seated  quietly,  with  head  erect,  we  suspend  a  piece  of  meat  on  a  thread 
and  move  it  along,  from  right  to  left,  on  a  level  with  her  eyes.  She  perceives  the 
odour  of  the  meat  and  makes  some  slight  movements  of  the  nose  as  dogs  do  when 
sniffing,  but  she  does  not  see  the  meat  in  the  temporal  sector  of  the  visual  field  at 
a  distance  of  25  cm.  from  the  eye.  As  the  piece  of  meat  reaches  the  line  of  the 
central  meridian  of  the  eye  she  sees  the  object,  draws  back  her  head  as  though  to 
recognise  it,  sniffs  more  strongly  and  makes  to  put  her  nose  up  to  it.  The  meat 
has  meanwhile  been  moved  further  on,  so  she  gets  up  and  follows  it.  Finally  she 
reaches  it  and  eats  it  greedily. 

If  pieces  of  meat  and  bread  are  scattered  on  the  floor,  she  sniffs  the  air,  then 
brings  her  nose  up  to  the  food  and  eats  with  avidity,  first  the  pieces  of  meat,  after- 
wards the  bread,  beginning  with  those  to  the  left  of  a  vertical  plane  passing  through 
the  visual  axis,  then,  sniffing  and  nosing  about,  eating  all  that  remains,  including 
those  that  have  fallen  much  outside  and  to  the  right  of  the  visual  field.  Sight  is 
certainly  improved  as  compared  with  its  condition  during  the  first  few  days  after 
the  operation  but  the  visual  field  has  a  decidedly  right  hemiopic  character. 

Both  eyes  being  covered,  her  hearing  is  now  examined.  When  the  tuning-fork 
is  brought  close  to  her  left  ear  she  reacts  as  before,  but  when  it  is  brought  up  to  the 
right  ear  (the  side  opposite  to  the  field  of  operation)  there  is  no  reaction  at  all ; 
it  seems  as  though  she  notices  nothing. 

Light  contacts  on  the  head,  ears,  back,  chest,  groin  and  tail  are  noticed  perfectly 
and  equally  on  both  sides  ;  moreover,  this  bitch  has  often  been  detected  getting  rid 
of  annoying  parasites  with  her  teeth  and  her  paws,  both  fore  and  hind. 

25th  July  1889. — Re-examined  to-day.  She  has  again  become  alert,  as  she  was 
prior  to  the  operation.  In  all  her  attitudes  there  is  no  difference  to  be  seen  as 
compared  /with  what  she  was  before.  No  sensory  or  motor  disturbance.  Sight 
also  is  improved  in  the  right  visual  sector,  apart  from  an  insignificant  uncertainty 
in  recognising  morsels  of  food.  Hearing  remains  almost  abolished  on  the  right 
side.  When,  however,  the  tuning-fork  is  brought  close  to  the  right  ear,  a  vague 
movement  of  the  ear  is  observed  and  the  bitch  assumes  an  attitude  of  attention. 

Killed  by  means  of  chloroform.  Autopsy.  On  removal  of  cranial  vault  a  large 
thick  cicatrix  is  seen  ;  it  is  adherent  to  the  decorticated  surface  of  the  left  hemi- 
sphere. It  is  now  detached.  The  brain  is  quite  normal  apart  from  the  left  temporal 
region.  The  parts  involved  are  a  portion  of  the  fourth  convolution,  the  middle 
part  of  the  third,  and  the  lower  border  of  the  middle  part  of  the  second  external 
convolution. 

After  hardening  in  formalin  solution  serial  sections  were  made.  No  further 
alterations  were  visible  to  the  naked  eye,  save  for  a  slight  dilatation  of  the  left 
lateral  ventricle. 

In  this  case,  the  hemi-hyposesthesia  and  amblyopia  were  phenomena  of  diaschisis 
and  were  very  slow  in  disappearing,  first  the  hemi-hypoaesthesia,  then  the  amblyopia, 
which  passed  into  bilateral  homonymous  hemianopsia.  Then  followed  phenomena 
of  compensation,  first  of  all  in  the  visual  function,  in  so  far  as  she  saw,  though  she 
did  not  recognise,  objects  in  the  right  (hemiopic)  visual  field  ;  and  finally  the 
deafness  of  the  right  side  lost  the  absolute  character  it  had  exhibited  for  about  two 
months.  One  can  understand  the  compensation  in  the  visual  function,  because 
only  a  portion  of  the  cortical  visual  field  had  been  injured.  Intelligence  and 
character  resumed  their  former  conditions. 

EXPERIMENT  3.— A  bitch  of  medium  size,  adult. 

She  walks  well,  jumping  motions  are  precise  and  there  is  no  disturbance  or 
defect  of  movement.  She  is  very  intelligent  and  lively. 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     143 

Sight  is  normal.  If  pieces  of  meat  and  bread  are  placed  promiscuously  on  the 
floor  at  various  distances,  she  selects  and  takes,  with  precise  movements  and  neat 
direction,  first  the  pieces  of  meat,  and  then,  as  she  is  still  hungry,  she  takes  and  eats 
the  pieces  of  bread  one  by  one  in  the  same  manner. 

Smell  also  normal.  If  pieces  of  bread  and  chalk  of  the  same  colour  are  thrown 
before  her  on  the  ground  she  takes  and  eats  with  rapidity  and  precision  the  pieces 
of  bread,  but  as  soon  as  she  brings  her  nose  up  to  a  piece  of  chalk,  «he  draws  back 
her  head  and  does  not  go  near  it  again. 

With  vulcanite  eye-shades  applied,  she  hears  the  slightest  noise,  and  always 
turns  her  head  and  eyes  in  the  direction  whence  it  comes,  in  a  listening  attitude. 

The  muscular  sense  is  well  preserved,  as  can  be  inferred  not  only  from  her 
movements  in  jumping  and  walking  but  also  from  the  precision  with  which  she 
seizes  a  piece  of  meat  in  the  air  as  it  is  thrown  to  her. 

In  two  days  she  has  learned  to  recognise  places  and  persons  and  she  shows 
affection  to  those  who  pet  and  make  much  of  her. 

Taken  for  the  first  time  into  the  laboratory  she  shows  herself  suspicious,  paws 
the  attendant  and  wishes  to  follow  him  alone.  Called  by  me,  she  hides  herself. 
If  the  attendant  goes  away  she  creeps  into  a  corner  and  remains  there  like  one 
afflicted  and  suspicious.  If  the  attendant  comes  back  into  the  room  she  becomes 
playful  again.  If  she  hears  a  noise,  especially  when  alone  with  us  in  the  observation- 
room,  she  pays  great  attention  to  it  and  turns  her  gaze  in  its  direction,  and 
sometimes  makes  to  go  out.  She  seems  docile. 

4th  March  1890. — Fairly  deep  narcosis  with  morphine  and  chloroform.  One 
attempt  only  at  vomiting. 

The  cranium  is  trephined  on  the  left  side  at  a  point  corresponding  to  the  middle 
part  of  the  second  external  convolution.  Incision  and  retraction  of  the  dura  mater; 
On  electrification  of  the  anterior  portion  of  the  exposed  area,  we  get  limited  con- 
traction of  the  orbicularis  palpebrarum  of  the  opposite  side.  On  using  a  stronger 
current  and  displacing  the  electrode  a  little  in  front  and  below,  but  still  keeping 
within  the  limits  of  the  second  convolution,  we  get  contraction  of  the  other  muscles 
of  the  right  side  of  the  face.  We  can  observe  a  slight  indication  towards  closing 
of  the  eyelids  on  the  left  side  (the  same  side  as  the  excited  hemisphere).  Behind 
this  very  excitable  area  comes  another,  where  even  a  comparatively  strong  excita- 
tion produces  no  effect.  Displacing  the  electrodes  yet  further  back  we  find,  still 
on  the  second  convolution,  a  third  area  which  is  excitable  with  a  weaker  current, 
its  effects  being  visible  on  the  extrinsic  muscles  of  the  eye  and  to  a  slight  extent 
also  on  those  of  the  iris,  for  medium  currents  induce  displacement  of  the  right 
(opposite)  eye  towards  the  right,  and  of  the  left  eye  also  towards  the  right,  though 
to  a  much  less  extent ;  and  further,  slight  dilatation  of  the  pupils.  I  now  demarcate 
the  central  inexcitable  zone  of  the  exposed  area,  making  vertical  incisions  with  a 
small  bistoury,  and  then,  with  a  small  spoon  with  cutting  edges,  I  scoop  out  the 
bridge  between  the  anterior  and  the  posterior  excitable  areas.  The  wound  being  now 
sutured  with  all  the  usual  precautions,  and  the  animal  liberated  (already  awake, 
for  the  experiment  has  lasted  over  twenty  minutes),  she  begins  to  walk  about  with 
a  slow  but  certain  gait.  On  closer  examination  it  is  distinctly  noted  that  she  no 
longer  winks  the  right  eye.  The  examination  is  now  deferred  to  another  day. 

1th  March  1890. — The  bitch  is  awake  and  in  her  usual  good  humour.  She  eats 
with  appetite  and  recognises  the  persons  who  bring  her  food,  exchanging  caresses 
with  them.  If  from  the  right  side  one  attempts  to  frighten  her  with  a  flash-lamp, 
a  stick,  or  in  any  other  way,  passing  these  in  front  of  the  right  eye,  she  takes  no 
notice  and  does  not  wink.  It  appears,  however,  that  she  may  notice  in  an 
indistinct  way,  for  she  will  turn  her  head  so  that  the  impression  falls  within  the 
visual  field  of  the  other  eye  or  on  the  extreme  left  of  the  right  eye  itself.  If,  stand- 
ing in  front  of  her,  we  place  on  the  floor  two  pieces  of  meat,  one  to  the  right  and  one 
to  the  left  at  equal  distances  from  the  vertical  of  the  nose,  she  takes  and  swallows 


144  THE  MECHANISM  OF  THE  BKAIN 

with  avidity  only  that  on  the  left  side,  although  she  is  hungry  through  having  been 
made  to  fast,  and  she  looks  in  my  hands  for  other  pieces.  If  instead  of  two  pieces 
of  meat  I  put  down  in  the  same  manner  a  piece  of  bread  to  the  left  and  a  piece  of 
meat  to  the  right,  she  pounces  upon  the  bread  and  does  not  see  the  meat.  If  I 
take  a  piece  of  meat  in  each  hand  and  pretend  to  throw  them  to  her  simultaneously, 
the  right  to  the  right  and  the  left  to  the  left,  she  turns  round  seeking  the  piece  on 
her  left  but  never  that  on  her  right.  If,  however,  I  gradually  bring  a  piece  of  meat 
close  up  to  the  median  line,  then  move  it  beyond  that  towards  the  internal  angle 
of  the  right  eye,  she  seizes  it  with  a  sufficiently  precise  movement.  Examination 
of  tactile  sensibility,  her  eyes  being  covered  with  the  gutta-percha  eye-shades,  gives 
negative  results.  There  is  no  disturbance  of  motion  or  of  hearing  on  either  side. 
Intelligence  and  humour  are  perfectly  well  preserved. 

2nd  April  1890. — Healing  by  first  intention.  If,  while  she  is  seated  on  her  hind 
quarters  with  head  erect,  a  person  standing  at  her  shoulders  advances  the  hand  or 
any  object  into  the  visual  field  from  the  side  of  the  lesion,  she  notices  it  immediately 
and  turns  towards  the  object  in  question,  If  the  experiment  is  repeated  on  the 
other  side — i.e.  the  side  opposite  to  the  lesion — she  does  not  notice  the  hand  or  any 
small  object  or  even  a  black  hat,  until  the  object  is  advanced  beyond  the  middle 
line.  During  the  examination  she  has  made  use  of  the  hind  paw  of  the  side  opposite 
to  the  lesion,  with  adequate  movements,  in  order  to  remove  some  irritation  from 
the  ear  of  that  side. 

The  bitch  is  always  quick  and  active,  walks  well,  avoids  all  obstacles,  except 
that  now  and  again  she  knocks  against  the  edge  of  the  doorway  on  the  right  side 
(opposite  the  lesion).  She  recognises  the  persons  who  take  to  do  with  her,  paws 
them  and  shows  affection.  She.  has  preserved  the  instinct  of  decency,  for  she 
neither  urinates  nor  messes  in  the  large  cage  where  she  is  kept  unchained,  but,  on 
putting  her  out,  she  runs  to  the  extreme  end  of  the  garden  and  there  urinates  at 
length  and  voids  the  bowels.  She  has  the  sense  of  appetite,  for  she  paws  and  jumps 
up  on,  and  makes  a  great  fuss  with,  the  man  who  is  in  the  habit  of  bringing  her  food. 
The  tactile  sense,  re-examined  with  care,  is  quite  normal.  She  scratches  herself 
equally  well"  with  the  hind  paw  of  each  side  so  as  to  remove  cutaneous  stimuli,  and 
with  her  muzzle  she  seeks  for  lice,  now  to  the  right,  and  now  to  the  left,  with  precise 
movements. 

Ocular  movements  and  tactile  and  painful  sensibility  of  the  ocular  conjunctiva 
are  normal  and  equal  on  both  sides. 

Hearing  is  well  preserved,  judging  from  her  reaction  to  the  tuning-fork  brought 
more  or  less  closely  up  to  the  ear.  In  all  the  tests  she  withdraws  her  head  from  the 
acoustic  stimulus  and  turns  herself  in  its  direction.  This  action  is  even  more 
evident  when  both  eyes  are  covered  with  vulcanite  eye -shades. 

When  the  left  eye  is  covered,  she  is  rather  more  cautious  in  her  movements.  She 
avoids  all  obstacles  but  as  though  she  has  difficulty  in  recognising  them.  She  seizes 
pieces  of  meat  thrown  to  her  and  runs  after  them,  but  her  movements  are  less 
precise.  Her  movements  are  greatly  aided  by  touch  and  smell. 

IQth  May  1890. — She  is  quick  and  active,  full  of  spirit,  affectionate  to  her  attend- 
ants, and  is  domesticated  even  with  the  doctors.  She  is  docile,  she  paws  those 
about  her,  she  runs  and  jumps,  showing  no  difference  in  the  two  sides.  She  turns 
her  head  now  to  this  side,  now  to  that,  and  curves  herself  up  in  every  fashion  and 
every  direction,  using  now  one  paw  now  another  to  rid  herself  of  troublesome  insects. 
No  difference  is  to  be  detected  in  the  two  sides,  however  delicate  the  stimuli 
applied  to  various  points  of  the  body. 

Sight  is  restored.  Employing  the  usual  method  and  covering  the  right  and  left 
eye  alternately,  a  proceeding  to  which  she  is  now  accustomed,  she  recognises  persons 
and  foods  and  runs  after  little  balls  as  they  are  thrown  away,  no  matter  which  eye  is 
open. 

She  is  killed  with  chloroform.     The  brain  on  removal  shows  a  lesion  limited  to 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES,  &  MONKEYS    145 

the  second  external  convolution,  hardly  encroaching  on  the  corresponding  lower 
border  of  the  first  external  convolution.  The  lesion  is  limited  in  front  at  a  point 
where  the  convolution  curves  round  below  following  the  bend  of  the  sigmoid  gyrus. 
Antero-posterior  vertical  sections  reveal  no  other  lesion  to  the  naked  eye,  apart 
from  the  fact  that  the  left  lateral  ventricle  is  dilated  as  compared  with  the  right. 

EXPERIMENT  4. — 16th  April  1889. — A  male  adult  dog,  robust,  lively,  quick, 
agile,  affectionate,  sociable  and  good-natured.  Senses  all  normal. 

I  expose  the  right  hemisphere  towards  its  anterior  extremity  laying  bare  part  of 
the  sigmoid  gyrus  and  the  frontal  extremity  of  the  hemisphere.  The  usual  move- 
ments of  the  limbs  are  provoked  by  faradic  excitation  of  the  sigmoid  gyrus.  In 
front  of  the  anterior  branch  of  this  gyrus  the  same  slight  electric  excitation  produces 
no  results.  On  increasing  the  strength  of  the  current,  movements  of  the  head  and 
eyes  to  the  opposite  side  are  induced. 

With  a  small  bistoury  I  make  a  deep  cut  into  the  grey  substance  and  scoop  out 
all  that  remains  of  the  hemisphere  in  front  of  the  presylvian  sulcus,  leaving  in  situ 
only  a  part  of  it  which  it  is  difficult  to  remove,  without  interfering  with  the  olfactory 
bulb  which  I  desire  to  spare.  The  wound  is  cleansed  of  blood  and  washed  with 
sublimate  solution.  The  edges  of  the  dura  mater  are  brought  together  and  sutured  ; 
asepsis  and  suture  of  the  overlying  tissues. 

18th  April  1889. — He  is  brought  into  the  observation-room  and  allowed  to  go 
free.  He  walks  well,  but  shows  slight  paresis  of  the  left  anterior  paw.  He  also 
exhibits  very  great  fear,  and  on  going  near  those  in  the  room  he  crouches  and 
cringes,  so  that  his  abdomen  touches  the  floor. 

24th  April  1889. — He  eats  regularly  from  the  usual  bowl.  Left  at  liberty  in  the 
garden  he  at  once  makes  off,  going  through  a  jumping  performance  in  the  middle  of 
the  path.  After  proceeding  a  few  yards  he  stops,  takes  a  turn  to  the  right,  looks 
back,  wanders  here  and  there,  showing  great  indecision  as  to  which  direction  to  take, 
as  though  arrested  by  a  sudden  remembrance.  He  finally  makes  off,  running  in  one 
direction,  then  suddenly  stops,  seems  undecided,  turns  back,  then  returns  in  the 
same  direction,  behaving  very  differently  from  what  he  did  prior  to  the  operation. 
Not  a  single  moment  does  he  remain  quiet,  as-  was  his  habit.  Called  in  the  usual 
way  by  me,  he  hears  and  runs  towards  me,  but  if  on  the  way  he  comes  across  a  pool 
of  water  or  any  other  object  on  which  his  glance  may  fall,  he  stops  and  noses  around 
it,  forgetting  to  come  up  to  me.  He  goes  into  a  furrow  in  the  garden  and  bites  off 
some  leaves  as  though  he  no  longer  recognises  them  as  such,  things  to  which  he  pre- 
viously paid  no  attention.  Never  a  moment  at  rest,  he  comes  to  a  rubbish-heap, 
jumps  up  on  it,  noses  around  and  carries  off  one  or  other  of  the  leaves  or  bits  of 
rubbish  which  he  finds  there.  He  does  not  readily  return  to  his  kennel,  so  that  one 
lias  to  get  hold  of  him  and  lead  him  back  on  a  leash.  He  does  not  react  to  visual 
stimuli  equally  on  both  sides,  for  he  does  not  recognise  objects  with  the  left  eye. 
Methodical  and  patient  examination  of  tactile  sensibility  shows  a  slight  diminution 
on  the  side  opposite  to  the  mutilated  hemisphere.  He  hears  equally  well  on  both 
sides,  shaking  his  ears  whenever  the  vibrating  tuning-fork  is  brought  near.  When 
he  walks  slowly,  accurate  observation  enables  one  to  detect  a  slight  paresis  of  the 
opposite  side  and  a  slight  sinking  of  the  pelvis,  with  the  convexity  upwards  and 
rather  to  the  left.  Priapism  has  been  practically  constant  for  ten  daj^s. 

21th  April  1889. — He  does  not  wink  the  eyelids  on  threatening  him  with  a  stick  or 
with  the  hand,  after  bandaging  the  right  eye.  He  does  not  readily  recognise  a  piece 
of  meat  held  between  the  fingers,  although  he  directs  his  gaze  towards  it.  As  he 
walks  he  avoids  obstacles,  but  displays  a  manifest  uncertainty  and  perplexity  in 
his  movements,  sometimes  rubbing  his  left  side  against  a  wall. 

3rd  May  1889. — He  is  much  improved,  more  cheerful  and  playful ;  he  jumps  up 
and  paws  now  one,  now  another,  of  the  persons  in  charge  of  him.  He  runs  hither 
and  thither  without  ever  knocking  himself.  From  a  distance  he  sees  a  bitch  that 
K 


146  THE  MECHANISM  OF  THE  BRAIN 

has  been  operated  upon  some  time  before  and  runs  to  play  with  her ;  though  chased 
away,  he  returns  again,  although  he  makes  no  attempt  at  copulation,  so  that  the 
caresses  he  bestows  on  the  bitch  differ  in  no  way  from  those  he  bestows  upon  the 
man  who  brings  him  his  food.  In  all  his  ceaseless  movement  and  rushing  about 
there  is  an  evident  agitation  which  seems  to  point  to  a  total  want  of  that  direction 
and  finality  which  we  observed  in  unmutilated  dogs.  Although  improved,  the 
animal  seems  unable  to  form  a  precise  judgment  of  anything  that  falls  under  his 
senses,  as  he  formerly  did,  so  that  not  only  does  he  walk  hither  and  thither  in  an 
aimless  way,  but  he  puts  his  nose  here  and  there,  to  right  and  to  left,  to  substances 
which  formerly  never  arrested  his  attention  (a  leaf,  a  medlar,  a  twig,  garbage  and 
filth  of  any  kind,  etc. ).  The  paresis  of  the  opposite  side  has  almost  disappeared,  and 
very  rarely  does  he  support  himself  on  the  dorsum  of  the  paw.  There  is  no  difference 
between  the  two  sides  as  regards  tactile  and  painful  sensibility.  The  vibrations  of 
the  tuning-fork  are  heard  equally  on  both  sides.  He  reacts  less  intensely  with  the 
eye  of  the  side  opposite  to  the  mutilated  hemisphere.  On  examining  his  sight  with, 
the  usual  methods  there  is  no  evidence  of  hemianopsia,  although  there  is  a  manifest 
defect  in  the  visual  recognition  of  objects  (foods)  which,  when  his  eyes  are  bandaged, 
he  can  recognise  with  the  aid  of  his  sense  of  smell. 

12th  May  1889. — The  dog  seems  completely  recovered.  He  is  brisk  and  lively, 
recognises  and  paws  the  persons  who  look  after  him  and  is  continually  jumping  up 
on  them.  No  disturbance  of  motion  is  to  be  detected  even  when  he  is  lifted  up  and 
suspended  by  the  thorax.  There  is  no  disturbance  of  sensibility,  for  he  reacts  to 
the  slightest  stimuli  on  both  sides  equally.  He  hears  equally  well  with  each  ear. 
The  only  thing  to  be  noticed  is  a  certain  difference  between  the  two  eyes  in  the 
manner  of  reacting,  in  the  sense  that  he  winks  the  left  eyelids  less  than  the  right. 
On  bandaging  one  or  other  of  the  eyes,  and  passing  objects  or  the  hand  in  front  of 
the  eye  of  the  side  opposite  to  the  mutilated  hemisphere,  he  shows  himself  markedly 
uncertain  and  confused  when  only  this  eye  remains  open,  and  not  when  it  is 
bandaged. 

Three  facts  are  worthy  of  note  : — (1)  Restlessness,  uncontrollable  and  incoherent. 
(2)  The  tendency  to  take  up  articles  which  did  not  before  attract  his  attention  (dry 
leaves,  twigs,  pieces  of  wood  and  filth).  (3)  The  priapism,  with  curvature  of  the 
trunk,  which  quite  disappeared  after  a  couple  of  weeks. 

I6th  May  1889. — The  conditions  mentioned  in  the  preceding  observations 
continue  as  before,  except  that  the  difference  in  sight  between  the  two  eyes  has 
gradually  diminished  until  it  has  practically  disappeared. 

Employing  the  same  methods,  I  again  open  the  cranium  on  the  other  side.  With 
a  faradic  current  various  points  of  the  anterior  convolution  of  the  sigmoid  gyrus  are 
excited,  provoking  the  usual  movements  of  the  limbs  and  especially  of  the  trunk  and 
head.  Excitation  of  the  posterior  extremity  of  the  frontal  lobe  provokes  only 
movements  of  the  head  and  eyes.  Further  forwards,  excitation  gives  no  reaction. 
With  a  sharp  bistoury  I  divide  off  all  the  cerebral  hemisphere  which  lies  in  front  of 
the  sigmoid  gyrus.  With  a  small  spoon  the  cortex  is  removed  and  the  wound  then 
closed. 

The  dog  is  very  helpless  and  quite  paralysed  in  both  fore  limbs.  He  remains 
for  hours  with  his  nose  on  the  floor  as  though  in  a  forced  position,  with  the  fore  paws 
curved  under,  the  hind  limbs  extended  and  raised,  as  though  he  were  trying  to  poke 
his  nose  into  a  hole  in  the  ground.  No  matter  when  or  how  we  remove  him  from 
this  position  he  takes  it  up  again,  always  returning  to  press  his  muzzle  on  the  ground. 

2lst  June  1889. — He  has  gained  greatly  in  strength.  When  the  door  of  the  room 
where  he  is  kept  is  opened,  he  threads  his  way  out,  walks  with  eyes  cast  down,  the 
head  inclined  forwards,  almost  touching  the  ground  with  his  nose.  He  no  longer 
paws  or  caresses  those  who  look  after  him.  He  wanders  here  and  there  in  a  stupid, 
awkward,  aimless  fashion.  When  called,  he  turns  and  walks  for  a  little  in  the 
direction  of  the  voice,  then  seems  to  forget  and  takes  another  direction.  If  we 


EXPEKIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     147 

obstruct  his  path  with  a  hat,  he  is  afraid,  and  stops,  and  does  not  seek  to  escape 
from  the  obstacle.  He  sees  equally  well  with  each  eye.  He  hears,  and  feels  tactile 
impressions  on  both  sides.  The  things  that  are  outstandingly  defective  are  vivacity, 
perceptive  promptitude  and  courage.  For  example,  he  exhibits  very  great  inco- 
herence in  his  movements,  and  a  tendency  to  take  into  his  mouth  anything  he  comes 
across,  which  next  moment  he  leaves  aside  with  equal  readiness.  He  wanders 
round  a  basin  like  one  famished,  first  in  one  direction,  then  in  the  other.  He 
stumbles  over  a  chain  holding  another  dog  which  has  undergone  an  operation  on  the 
occipital  lobes.  The  latter  is  blind,  and,  feeling  himself  jerked  and  not  knowing  the 
reason,  bites  the  first  dog,  which,  in  a  state  of  fear,  merely  doubles  himself  up, 
without  seeking  to  escape  from  the  violent  attacks  of  the  other,  so  that  it  is  necessary 
to  remove  him  forcibly  from  his  awkward  situation.  Soon  after,  he  returns  to  the 
same  place  and  a  similar  scene  is  enacted.  Still,  a  third  time,  he  goes  back,  and  on 
this  occasion  the  other  dog  attempts  to  mount  on  him  whilst  he,  instead  of  making 
off  or  defending  himself,  merely  takes  to  howling. 

5th  July  1889. — The  same  condition  of  things  persists — incoherence,  errors  of 
judgment,  restlessness,  stereotypism,  indifference.  If  taken  out  to  the  garden 
paths,  he  runs  about  stupidly  and  without  signs  of  tiring,  stooping  now  and  again  to 
pick  up  pieces  of  dry  grass  and  filth.  If  called,  he  turns  back  in  the  direction  of  the 
voice  or  whistle,  but  at  a  certain  point  forgets  and  goes  his  own  way.  If  he  reaches 
a  space  where  there  is  a  fountain,  he  runs  round  it  many  times  in  succession,  stops 
for  a  little,  and  then  without  any  reason  runs  off  again.  If  left  to  himself  in  the 
spacious  garden,  he  does  not  again  return  to  his  kennel,  but  wanders  about  here 
and  there  in  an  aimless  manner.  He  does  not  follow  anyone.  The  sense  of  smell  is 
unaffected ;  with  his  eyes  bandaged  he  picks  up  at  once,  if  hungry,  pieces  of  meat 
thrown  20  to  30  cm.  in  front  of  him.  Sight  is  normal ;  the  visual  field,  measured 
by  the  usual  methods,  is  normal.  He  picks  up  everything  with  precise  movements. 
All  trace  of  paresis  of  the  limbs  has  disappeared.  He  can  move  his  head  in  all 
directions  and  raise  it  high,  as  is  evident  when  shown  a  piece  of  meat  suspended 
30  to  40  cm.  above  his  head. 

20th  July  1889. — He  remains  in  the  same  condition.     Killed  with  chloroform. 

At  the  post-mortem  examination  the  whole  brain  appears  normal  except  in 
front,  where,  at  a  point  corresponding  with  the  trephine-opening,  there  exists  a 
thick  cicatrix  which  has  to  be  detached  gradually  with  the  scalpel  in  order  not  to 
tear  the  normal  margins  of  the  brain.  The  crucial  sulcus  is  normal  on  both  sides. 
The  anterior  and  posterior  branches  of  both  sigmoid  gyri  are  normal,  except  a 
small  portion  of  the  anterior  branch  of  the  left  sigmoid  gyrus  which  has  been 
injured  in  the  operation  and  is  included  in  the  cicatrix. 

This  brain  was  kept  and  prepared  for  the  investigation  of  degenerations  secondary 
to  the  extirpation  of  the  frontal  lobes. 

* 
*  * 

In  this  case  we  have  had  very  definite  evidence  of  serious  alterations  of  character, 
affecting  all  the  intellectual  and  emotional  processes.  These  changes  made  them- 
selves apparent  from  the  outset  and  were  persistent.  They  could  not  be  attributed 
to  paralysis  of  the  trunk  and  limbs,  because  that  was  fleeting  ;  nor  to  disturbances 
of  sight,  because  this,  too,  disappeared,  although  the  psychic  conditions  in  no  way 
improved,  and  this  could  only  be  the  effect  of  the  lesion  of  the  anterior  lobes. 

Summing  up  the  results  of  all  the  experiments  we  have  carried  out  on  dogs, 
it  is  to  be  observed  that  in  almost  every  case  we  had  occasion  to  note  changes  in 
character  and  limitation  of  the  mental  powers  as  the  result  of  mutilation  of  the 
frontal  lobes.  With  these  we  shall  deal  subsequently.  In  addition,  we  had  nearly 
always  to  notice  visual  disturbances,  consisting  of  bilateral  hemianopsia,  much 
more  evident  in  the  eye  of  the. opposite  side.  These  disturbances  were  always 


148  THE  MECHANISM  OF  THE  BRAIN 

transitory,  except  in  one  case  in  which  we  found,  at  the  autopsy,  softening  of  the 
occipital  lobes.  There  was  also  observed  paralysis  of  the  trunk  with  lumbar 
curvature  and  drooping  of  the  head,  but  this  was  fleeting.  The  paresis  of  the 
opposite  fore  limb,  sometimes  also  of  the  posterior  limb,  was  transitory,  and  on 
each  occasion  the  autopsy  showed  a  limited  lesion  of  the  anterior  branch  of  the 
sigmoid  gyms,  of  which,  however,  the  greater  part  was  well  preserved.  Disturb- 
ances of  general  sensibility  were  very  rare  and  of  a  fleeting  character  (the  area  of 
sensibility  was  almost  always  spared).  We  had  no  disturbances  of  hearing,  hunger 
or  thirst.  So  far  as  the  sexual  instinct  or  appetite  is  concerned,  it  seemed  not  to  be 
abolished  in  the  dogs  experimented  upon,  although  sexual  boldness,  which  is  quite 
another  thing,  was  absent. 

EXPERIMENT  5. — 15th  August  1889. — A  young  vixen  of  4£  to  5  months,  well 
developed.  It  has  been  found  impossible  to  tame  her  ;  so  wild  is  she  that  she  has 
proved  quite  refractory  to  the  various  plans  we  have  tried  to  make  her  docile. 
Though  still  small,  she  can  bite  like  anything.  Confined  in  a  large  iron  cage,  she 
showed  herself  quite  indifferent  to  all  kindly  attentions  and  to  the  preferential 
treatment  meted  out  to  her,  as  compared  with  the  other  animals  in  the  institute. 
More  than  once  when  taken  out  of  her  cage,  she  nearly  strangled  herself  in  her 
attempts  to  escape,  tugging  madly  and  obstinately  at  the  chain  or  leash  attached 
to  her  neck. 

Very  fond  of  meat  and  milk.  She  made  her  diet  almost  exclusively  of  these. 
Inside  and  outside  her  cage  she  appeared  to  have  only  one  instinct — that  to  escape. 
Every  time  the  cage  was  opened,  she  spied  around  to  see  how  she  could  jump  out, 
and  in  this  no  doubt  she  would  have  succeeded  had  she  not  been  secured  inside 
the  cage  with  a  chain.  Her  eyes  were  always  wide  open,  suspicious,  stealthy, 
and  her  ears  always  on  the  alert.  The  slightest  noise  brought  her  to  attention. 
Quite  unsociable,  she  has  never  shown  any  sign  of  gratitude  or  recognition  towards 
the  person  who  has  charge  of  her,  but  rather  a  most  obstinate  diffidence  ;  nor  is 
she  any  better  disposed  towards  other  animals,  dogs  and  monkeys,  in  her  vicinity. 
She  has  always  been  quite  indifferent  and  has  never  shown  the  slightest  semblance 
of  sociability  or  adaptability  during  more  than  two  months. 

1 5th  August  1889. — She  is  anaesthetised.  Following  the  usual  methods,  the  frontal 
pole  and  sigmoid  gyms  on  both  sides  are  laid  bare,  the  dura  mater  having  been 
incised  and  turned  aside.  Electric  excitation  is  now  employed  with  the  following 
results  :  — 

(a)  All  the  part  lying  in  front  of  the  sigmoid  gyrus  is  not  excitable,  with  the 
Du  Bois  Reymond  sledge  at  10  cm.  (a  current  which  was  left  fairly  strongly  on  the 
tongue  and  lips). 

(6)  On  the  anterior  branch  of  the  sigmoid  gyrus  the  same  strength  of  current 
produced,  at  a  point  above,  dilatation  of  the  pupil  of  the  opposite  side,  and  a  slight, 
but  strong  and  rapid,  movement  of  the  head  towards  that  side  ;  below,  rapid  and 
marked  dilatation  of  both  pupils,  ceasing  immediately  the  current  is  broken,  and 
movements  of  the  trunk  and  tail  ;  with  a  stronger  current,  slight  movements  of 
the  limbs  of  the  opposite  side  are  also  induced. 

(c)  On  the  posterior  branch  of  the  sigmoid  gyrus  we  find  arranged  in  succession, 
almost  as  in  the  sigmoid  gyrus  of  the  dog,  the  various  centres  of  the  muscles  of  the 
limbs  and  of  the  trunk. 

It  is  unnecessary  to  enter  into  further  particulars  in  this  respect.  Having 
repeated  the  excitations,  and  made  sure  of  the  constancy  and  uniformity  of  the 
results  of  the  electric  stimulation,  and  especially  of  the  fact  that  excitation  of  the 
posterior  branch  of  the  sigmoid  gyrus  produces  no  effect  upon  the  irises,  we  scoop 
out,  following  an  inclined  plane,  all  that  remains  in  front  of  the  sigmoid  gyrus  and 
a  small  portion  of  the  anterior  branch  of  the  sigmoid  gyrus,  leaving  the  most  of  it 
uninjured,  with  the  sole  object  of  avoiding  damage  of  any  kind  either  to  the  cortex 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     149 

or  the  projection  fibres  of  the  motor  centres  arranged  mostly  on  the  posterior 
branch  of  the  sigmoid  convolution.  Very  scanty  haemorrhage  ;  closure  of  wound  ; 
antiseptic  dressing. 

After  six  hours,  having  revived  from  the  stupefaction  produced  by  the  morphine 
and  the  injury,  the  vixen  gets  up,  runs  about  all  over  the  cage  with  head  straight 
and  erect  as  usual,  the  eyes  wide  open,  the  ears  attentive.  No  deviation  of  the 
trunk  is  detected,  no  disorder  or  defect  in  the  movements  of  the  limbs,  no  bending 
of  the  paw  or  resting  on  the  dorsum,  no  doubling  of  the  limbs  under  the  weight  of 
the  body. 

Tactile  sensibility. — If,  from  behind,  we  put  a  very  thin  wand  through  the  cage 
and  touch  her  lightly  on  any  point  whatsoever  of  the  body  on  either  side,  she  reacts, 
either  turning  her  head  towards  the  side  on  which  she  is  touched  or  rising  and 
recommencing  her  round  of  the  cage. 

Hearing. — If  the  tuning-fork  is  brought  up  to  her  ear  on  either  side,  she  shows 
surprise.  If  at  some  distance  away  we  make  a  noise  on  the  terrace  as  by  a  slight 
shaking  of  the  chain,  or  if  in  the  room,  at  10  metres  distant,  we  make  a  sudden 
bang  on  the  table  she  immediately  stands  erect,  turns1  her  head  and  eye  towards 
the  point  whence  came  the  noise  and  remains  on  the  alert. 

Sight. — The  eyes  of  this  little  beast  have  lost  their  former  vivacity  ;  they  have 
no  longer  the  savage,  inquiring,  suspicious  glance  ;  they  seem  like  artificial  eyes 
implanted  in  the  orbits  of  a  living  face.  The  gaze  is  directed  into  space.  If  we 
threaten  her  or  bring  a  stick  or  the  hand  close  up  to  her  eye,  as  though  to  strike  her, 
she  never  winks.  If,  however,  we  lightly  touch  the  eyelids  and  more  especially  the 
conjunctiva,  either  on  the  right  or  on  the  left  side,  the  reflex  movements  of  the  lids 
are  found  to  be  ready  and  lively. 

Sometimes,  as  she  is  going  around  in  the  cage,  she  knocks  her  nose  against 
the  iron  bars,  especially  on  the  left  side. 

Slight  winking  is  got  in  the  right  eye,  if,  taking  her  by  surprise,  a  fairly  large 
body  such  as  the  closed  fist  is  brought  up  to  the  eye  from  that  side.  Corresponding 
with  this  difference  in  the  behaviour  of  the  two  eyes  is  the  fact  that,  in  order  to  see, 
she  almost  always  turns  towards  the  right,  and  she  prefers  to  go  (or  automatically 
is  forced  to  go)  towards  the  right,  reminding  one  of  a  circus  movement. 

\1tk  August  1889. — There  is  no  trace  of  swelling  nor  of  suppuration.  The  animal 
exhibits  agitation  and  restlessness  while  in  the  cage  and  is  extremely  terrified. 
We  set  her  at  liberty  in  a  room,  in  the  middle  of  which  there  are  several  chairs 
scattered  about,  giving  her  a  hen  for  a  companion.  She  at  once  makes  off,  skirts 
the  walls,  stops  at  the  corners  and  jumps  as  though  attempting  to  get  out,  clamber- 
ing up  the  walls  where  there  is  neither  window  nor  opening  of  any  kind.  She 
avoids  all  the  obstacles,  but  wherever  there  is  an  opening  she  forces  herself  into  it 
at  all  costs,  knocking  aside  the  obstacles  as  though  she  were  being  chased.  She 
is  agitated  and  terrified  and  pays  no  attention  to  the  fowl.  She  rests  steadily  on 
her  legs,  which  sometimes  are  crossed  and  sometimes  are  wide  apart ;  for  the  rest, 
she  is  very  agile  and  runs  around  in  an  effort  to  escape,  jumping  and  clambering 
up  the  walls. 

Tactile  sensibility  is  well  preserved.  If  touched  anywhere,  especially  if  taken 
by  surprise,  she  reacts  by  shaking  herself  and  running  away.  She  hears  the  slightest 
noises.  Her  eyes  still  remain  immobile  and  vacuous  as  though  staring  into  space, 
especially  the  left. 

22nd  August  1889. — Paresis  has  almost  disappeared.  Hearing  and  cutaneous 
sensibility  are  normal  as  before.  Her  glance  is  less  vacuous  ;  she  seems  to  direct 
it  better  and  accommodation  is  more  perfect.  She  does  not  wink  yet,  when 
threatened  with  a  stick,  or  when  the  hand  is  suddenly  brought  up  to  her  eye,  but 
she  certainly  notices  the  approach  of  any  person  or  object,  because  she  directs  her 
gaze  thereto  and  recoils  in  terror,  puffing  and  blowing. 

She  is  extremely  restless.     For  hours  together  she  goes  from  one  corner  to 


150  THE  MECHANISM  OF  THE  BRAIN 

another  of  her  cage  in  the  same  identical  fashion,  reminding  one  of  a  stereotyped 
movement. 

1st  September  1889. — Wound  healed  by  first  intention. 

She  takes  her  milk  and  meat  as  before.  She  recognises  foods  placed  in  a  corner 
of  the  room  and  eats  regularly. 

She  is  always  restless  and  indifferent.  She  shakes  with  fear  at  every  noise  and 
at  every  pretence  of  hurting  her,  soon  afterwards  recommencing  her  automatic 
movements  hither  and  thither,  almost  always  in  the  same  direction,  whether  in 
the  cage  or  in  the  room.  This  automatic  monotony  is  only  broken  by  any  noise 
which  frightens  her  for  the  moment. 

12th  September  1889. — All  the  nervous  functions  are  again  accurately  examined. 
Tactile  and  painful  sensibility,  examined  in  the  usual  fashion,  is  normal.  Hearing 
perfect ;  her  eyes  being  covered  with  caoutchouc  eye -shades,  she  hears  the  slightest 
vibrations  of  the  tuning-fork  slowly  approximated  to  her  ear,  and  equally  on  each 
side.  On  removing  the  vulcanite  eye-shades  she  makes  movements  with  her  paws 
over  her  eyes  as  though  to  remove  some  stimuli,  just  as  men  rub  their  eyes  after  a 
troublesome  foreign  body  is  removed,  then  turns  her  head  around  and  recommences 
the  stereotyped  movements.  She  does  not  knock  against  the  wall  nor  against  any 
chair  or  other  piece  of  furniture.  She  avoids  them  all.  She  sees  her  milk  in  a 
corner  of  the  room  and  goes  to  drink  it.  Pieces  of  meat  are  thrown  to  right  and 
left  at  some  distance  in  front  of  her  ;  she  sees  them  and  takes  them  up  with  precise 
movements  then  begins  again  her  stereotyped  motions.  If  her  head  and  trunk 
are  maintained  in  a  fixed  position  in  a  dark  room  and  we  now  enter  with  a  bull's- 
eye  lantern,  she  at  once  notices  the  light  and  turns  her  eyes  towards  it,  to  the 
right  or  to  the  left,  to  the  extreme  external  limit  of  the  visual  field. 

On  this  occasion  we  have  been  able  to  observe  the  pupillary  reaction  very 
distinctly,  and  especially  the  marked  contraction  when  the  light  of  the  lantern 
penetrated  directly  into  the  eye. 

llth  September  1889. — Found  dead  from  strangulation,  with  her  chain  twisted 
around  her  neck. 

EXPERIMENT  6. — Ciacma  cynocephalus  porcarius,  adult,  female,  intelligent. 
She  walks  on  all  fours  or  on  the  hind  limbs  alone,  at  the  word  of  command.  She 
gives  the  military  salute,  understanding  the  command  without  any  sign  being  given. 
She  takes  up  or  lays  down  her  stick  as  ordered  by  word  of  mouth  and  without  signal. 
She  also  shows  a  good  deal  of  intelligence  in  arriving  at  new  and  spontaneous 
adaptations  in  the  various  new  positions  in  which  she  finds  herself — e.g.  raising  or 
lowering  a  roller-shutter  which  gives  access  to  a  balcony.  She  distinguishes 
various  food  materials  and  shows  an  evident  and  distinct  preference  for  some 
rather  than  others.  She  displays  the  faculty  of  observation  and  fairly  well  developed 
sentiments  of  affection,  as  evidenced  by  her  behaviour  towards  another  male 
monkey,  operated  on  several  days  previously,  for  it  was  clear  that  it  was  not  always 
characterised  by  merely  erotic  tendencies,  even  during  her  menstrual  periods. 
She  often  embraces  him  and  shows  rudimentary  kissing  movements,  holding  him 
close  to  her  breast  in  an  attitude  almost  of  ^cstasy  and/evident  satisfaction.  This 
sentiment  of  affection  is  even  more  evident  with  two  puppy  dogs  to  which  she  has 
been  much  attached  from  the  moment  she  first  saw  them  and  has  tended  like 
a  mother.  The  following  observation  was  made  six  days  before  the  operation. 

23rd  May  1892. — To-day,  whilst  tied,  a  small  puppy  dog  happens,  by  chance, 
to  come  near  her.  She  looks  at  him  with  an  air  of  surprise  and  curiosity,  then 
takes  him  up  carefully  in  her  arm,  bestowing  on  him  a  thousand  caresses  and  showing 
all  the  care  and  anxiety  that  a  mother  might  feel  for  her  young  offspring.  She  sets 
the  puppy  down  and  follows  him  as  he  walks,  but  if  he  begins  to  go  too  far,  so  that 
she  cannot  follow  him  because  confined  with  her  chain,  she  takes  him  up  gently  in 
her  arm,  carries  him  back  and,  from  fear  of  losing  him,  keeps  him  embraced,  then 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     151 

sets  him  on  her  lap,  keeping  him  slightly  raised  with  one  arm  passed  under  his  chest. 
It  is  impossible, (either  wjj^r^iajjeiej:jc't5^with  threats,  to  make  her  leave  him.  If, 
when  at  last  she  does  set  him  down  on  the  ground,  we  try  to  call  the  puppy  in  the 
ordinary  way  but  without  giving  any  sign  that  would  make  the  other  suspicious, 
she  immediately  understands  the  whistle  and  at  once  takes  him  up  again  and  hugs 
him  to  her  breast.  If  now  we  seek  to  intimidate  her  with  a  stick,  matters  become 
worse.  She  shouts  and  becomes  angry,  and,  holding  the  puppy  closely  to  her,  but 
so  that  she  shall  not  hurt  him,  she  clambers  up  the  iron  railings  of  the  terrace 
in  order  to  keep  him  in  safety  as  far  as  possible. 

With  great  difficulty  we  succeed  in  taking  him  from  her.  After  a  little  I  take 
him  back  again  to  her.  She  manifests  great  satisfaction  and  several  times  she 
comes  up  to  me  as  though  in  gratitude  and  recognition,  although  there  are  several 
people  looking  on,  and  she  puts  out  her  hand  to  me  so  that  I  may  stroke  it. 

We  now  bring  in  a  second  puppy  dog.  He  begins  to  walk  around  her.  She 
looks  at  him,  smells  him,  touches  him,  but  does  not  take  him  in  her  arm,  rather  does 
she  seem  quite  indifferent.  As  soon,  however,  as  the  puppy  is  about  to  get  out  of 
her  reach  she  grasps  him  by  the  tail  and  slowly  and  gently  draws  him  back  towards 
her.  This  scene  is  repeated  several  times.  When  she  rises  to  go  from  one  point  to 
another  she  takes  the  first  puppy  in  one  arm,  and  with  the  other  hand  draws  the 
other  puppy  by  the  tail.  She  emits  guttural,  mournful-like  sounds.  Sometimes  she 
places  them  on  her.  knees,  and  with  the  fingers  of  both  hands  she  seeks  for  lice 
amongst  the  hair  of  the  neck,  in  almost  human  manner. 

It  has  been  impossible  to  take  them  from  her  at  close  quarters.  If  anyone 
approaches  her  she  seizes  both,  one  in  each  arm,  and  seeks  as  far  as  possible  to  put 
them  into  safety. 

In  order  to  make  her  lay  them  down  it  has  been  necessary  to  have  recourse  to  a. 
jet  of  water.  Of  this  she  has  a  great  fear,  and  it  is  sufficient  to  let  her  see  the  hose 
pipe,  when  she  will  commence  to  cry  and  make  a  great  noise.  Notwithstanding  the 
stream  of  water  she  has  kept  the  two  puppies  in  her  embrace  for  quite  a  long  time, 
trying  to  protect  them  as  well  as  possible.  Failing  in  this  she  has  put  down  the 
second  puppy,  and,  with  the  other  in  her  arm,  has  jumped  up  on  the  iron  railing. 
At  length,  able  to  bear  it  no  longer,  she  has  come  down  again,  has  carefully  and  slowly 
put  the  puppy  on  the  ground,  and  has  again  clambered  up  on  the  railing. 

29th  May  1892. — To-day  we  have  operated  on  the  frontal  lobe  of  the  left  side, 
employing  the  usual  method  already  described,  and  removing  about  3^  grm.  of 
cerebral  substance,  covering  an  area  a  little  more  than  2  cm.  sq.  in  front  of  the  feet 
of  the  first  and  second  convolutions,  leaving  the  frontal  pole  in  situ.  Slight 
haemorrhage  during  the  operation. 

30th  May  1892. — In  the  morning  hours  she  has  been  fevered,  but  towards  2  P.M. 
her  temperature  has  again  become  normal.  During  the  entire  day  she  has  been 
rather  low  and  depressed,  but  it  has  been  possible  to  give  her  some  nourishment. 

2nd  June  1892. — There  is  paresis,  of  the  left  side.  In  walking  she  makes  use  of 
her  four  limbs,  and  has  sufficient  strength  to  avoid  falling  on  the  pare  tic  side.  Loss 
of  power  on  the  right  side  is,  however,  quite  distinct.  When  she  jumps  it  is  evident 
that  she  supports  herself  chiefly  on  the  limbs  of  the  left  side,  and  to  a  slight  extent 
on  the  right  hind  limb,  which  is  stronger  than  the  right  fore  limb.  In  the  position 
of  rest,  the  paralytic  attitude  of  the  extremity  of  the  right  fore  limb  is  very  evident. 
She  is  no  longer  able  to  give  the  military  salute,  and  threats  do  not  help  matters. 
She  cannot  make  use  of  the  right  fore  limb  to  take  hold  of  any  object,  and  if  we  force 
her  to  employ  this  limb  by  holding  the  other,  it  requires  considerable  effort,  the 
object  readily  falls  from  her  hand,  and  she  fails  altogether  to  bring  it  to  her  mouth. 

She  can  raise  herself  on  the  flexed  hind  limbs,  but  cannot  stand  erect  on  the  feet 
as  she  formerly  did  with  ease. 

Vision  is,  at  least,  much  weakened  in  the  external  segment  of  the  visual  field  of 
the  right  eye,  and  the  internal  segment  of  that  of  the  left  eye,  so  that  she  cannot 


152  THE  MECHANISM  OF  THE  BRAIN 

recognise  the  nature  of  an  object  presented  to  her  in  those  parts  of  the  two  visual 
fields,  although  she  can  recognise  it  readily  in  the  other  segments.  The  test  has 
been  made  in  the  usual  way  by  suspending  to  a  thread  a  fruit  of  which  she  is  very 
fond,  and  bringing  it  horizontally  from  without  inwards  and  from  within  outwards 
before  each  eye.  Her  favourite  fruit  in  the  month  of  June  is  the  cherry,  which  she 
immediately  seizes  as  soon  as  she  recognises  it. 

5th  June  1892. — She  walks  well.  There  are  no  circus  movements.  She  does  not 
make  use  of  the  right  hand,  and,  if  offered  a  cherry,  takes  it  only  with  the  left.  If 
she  takes  hold  of  a  table  in  the  attempt  to  see  -what  is  on  it,  or  if  she  tries  to  open 
the  door,  it  is  always  with  the  left  hand.  She  never  oilers  anyone  the  right  hand. 
She  no  longer  salutes  with  th?  right  hand  as  she  formerly  did,  raising  herself  on 
her  hind  limbs,  grasping  her  tail  with  the  left  hand,  and  bringing  the  right  to  the 
forehead  in  a  military  fashion. 

If  we  hold  her  left  hand  and  offer  her  a  cherry,  she  repeatedly  makes  a  great 
effort  with  the  right  and  finally  succeeds  in  taking  it,  but,  lacking  the  power  to  raise 
it  to  her  mouth,  she  waits  passively  till  her  left  hand  is  liberated,  and  with  it 
immediately  puts  the  cherry  in  her  mouth. 

She  hears  the  tuning-fork  and  reacts  equally  on  both  sides. 

She  does  not  see  the  cheriy  well  until  it  is  brought  into  the  visual  field  from 
without  inwards  to  a  point  corresponding  to  the  median  vertical  axis  of  the  right 
eye. 

She  scratches  the  right  side  of  her  nose  and  occiput  with  the  right  hind  limb  and 
the  left  fore  limb. 

She  shows,  as  formerly,  a  capacity  for  new  adaptations  and  sentiments.  On 
again  presenting  to  her  the  puppy  towards  which  she  formerly  showed  great  affec- 
tion, she  takes  hold  of  him  gently,  embraces  him,  hugs  him,  takes  him  up  tenderly 
in  her  left  arm,  begins  to  search  amongst  the  hair  for  lice,  and,  as  she  cannot  move 
her  right  hand  as  formerly,  she  makes  adept  use  of  her  left  hand  and  her  teeth  in 
this  operation.  Woe  to  anyone  who  takes  the  puppy  away.  She  becomes  angry, 
cries  out,  and  is  desperate.  Being  unable  to  jump  up  on  the  chair  with  the  puppy 
in  her  arm  she  first  places  him  on  the  chair  and  jumps  up  after  him.  The  second 
puppy,  which  had  also  previously  been  presented  to  her,  has  not  met  with  the 
same  favour,  rather  does  she  avoid  him.  Of  four  puppies  she  shows  a  liking  for  her 
first  acquaintance  alone.  If  we  call  the  four  puppies  around  her  she  takes  up  her 
favourite  and  hugs  him  all  the  more  closely  to  her  breast. 

28th  June  1892; — The  paretic  limbs  have  gained  still  more  in  strength,  and, 
although  she  prefers  to  use  the  sound  arm  for  small  movements,  and  when  she  has 
free  choice,  yet  if  compelled  by  necessity,  she  can  also  make  use  of  the  other  arm, 
and  with  it  perform  movements  with  certainty. 

Sight  on  the  side  opposite  to  the  operation  has  improved.  Vision,  however,  is 
not  yet  quite  distinct,  for  although  the  monkey  notices  anything  which  falls  within 
the  blind  visual  field  and  turns  her  gaze  towards  it,  she  does  not  recognise  it  and 
makes  no  attempt  to  grasp  it ;  the  process  is  limited  to  the  turning  of  the  head  and 
gaze  towards  the  object,  the  light  from  which  falls  within  the  temporal  visual  field 
of  the  right  eye  or  nasal  of  the  left. 

\Qth  August  1892. — Second  operation. — This  time  a  trephine  opening  is  made 
over  the  right  frontal  lobe,  at  a  point  corresponding  to  the  feet  of  the  frontal  con- 
volutions. Faradic  excitation  of  the  upper  and  posterior  part  of  the  superior 
frontal  convolution  provokes  contractions  of  the  nape  of  the  neck.  The  head  is 
turned  towards  the  left.  At  a  point  some  millimetres  below,  we  obtain  movements 
of  the  head  and  eyes  to  the  opposite  side.  Still  further  below,  we  provoke  move- 
ments of  the  eyes  alone,  with  dilatation  of  the  pupil  of  the  opposite  side.  Still  lower 
down,  we  get  movements  of  the  pericranium,  of  the  opposite  side.  Movement  of  the 
pavilion  of  the  ear  alone  is  given  by  a  small  area  slightly  removed  from  that  which 
awakens  contractions  of  the  pericranium  and  of  the  pavilion  simultaneously. 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES,  &  MONKEYS    153 

We  remove  about  four  grammes  of  cerebral  cortex.  The  incision  falls  precisely 
in  front  of  the  feet  of  the  first  and  second  frontal  convolutions,  and  we  endeavour  to 
remove  all  that  portion  of  the  frontal  lobe  lying  in  front  of  the  incision.  Consider- 
able loss  of  blood. 

About  two  hours  after  the  operation  the  patient  is  able  to  drink  a  glass  of 
milk. 

19th  August  1892. — A  large  swelling  has  formed  over  the  site  of  operation.  No 
fever.  The  animal  is  able  to  stand  erect  on  the  hind  limbs,  but  her  support  on  the 
left  limb  seems  less  secure.  When  she  walks  on  all  four  paws  she  drags  the  left  fore 
limb.  She  shows  a  marked  tendency  to  circus  movement,  this  being  displayed 
towards  the  right  side.  Reflex  excitability  is  markedly  increased  on  both  sides  ; 
fairly  light  taps  provoke  tumultuous  jerks.  Almost  complete  blindness  in  the  left 

eve- 

24th  August  1892. — Circus  movement  continues  though  it  is  less  marked.  Rest- 
lessness, almost  vertiginous,  is  persistent.  She  jumps  up  on,  and  down  from,  a  chair 
placed  near  her.  She  knocks  it  down,  pulls  it  after  her  or  pushes  it  away,  or  shakes 
it  and  grasps  it  in  various  ways.  She  opens  and  shuts  the  door  on  the  balcony, 
tugs  repeatedly  at  the  chain  which  confines  her,  or,  if  not  performing  any  of  the  acts 
mentioned,  she  again  goes  through  the  circus  movement.  These  actions  resemble 
stereotyped  movements.  She  is  sufficiently  accurate  in  her  movements  to  prevent 
the  chair  from  falling  on  her  head,  and  to  avoid  knocking  herself  against  other 
objects,  but  she  immediately  goes  through  the  same  performance  again  and  exposes 
herself  to  the  same  inconveniences.  She  shows  no  concern  for  anyone  approaching 
her,  and  no  interest  in  what  is  happening  around  her.  Often,  when  called  re- 
peatedly, she  does  not  respond  but,  rather,  shows  an  extraordinary  fear,  such  as  she 
never  exhibited  before.  She  often  shows  herself  afraid  of  another  monkey  if  the 
latter  goes  near  her,  whilst  formerly  she  would  clasp  him  to  her  breast  in  ecstasy, 
perhaps  erotic,  perhaps  simply  tacto-emotional.  She  shows  an  indifference  towards 
many  things  in  which  she  formerly  evinced  a  lively  interest;  thus,  e.g.,  she  cares 
nothing  for  the  puppy  towards  which  she  was  formerly  so  affectionate,  and  even 
shows  fear  of  him  when  he  is  placed  beside  her. 

The  reflex  hyper-excitability,  so  marked  in  the  first  few  days,  is  diminished. 
jThe  right  ear  seems  more  sensitive  than  the  left  to  the  sound  of  the  tuning-fork. 

With  the  object  of  examining  the  sense  of  taste,  we  place  side  by  side  on  the  palm 
of  the  hand  a  piece  of  sugar  and  a- piece  of  chalk,  taking  care  that  they  should  re- 
semble one  another  in  form  and  volume  as  far  as  possible,  and  offer  them  to  her  to 
eat.  As  the  piece  of  chalk  is  placed  a  little  nearer  her  she  takes  it,  puts  it  in  her 
mouth,  and  one  cannot  detect  in  her  physiognomy  any  sign  either  of  pleasure  or 
disgust,  for  she  masticates  it  and  finally  swallows  it.  She  is  then  given  the  piece  of 
sugar  to  eat.  This,  like  the  chalk,  she  masticates  automatically  and  then  swallows 
without  exhibiting  any  sign  of  pleasure.  The  experiment  is  now  repeated,  and  even 
this  second  time  her  hand  is  directed  to  the  piece  of  chalk,  which  is  a  few  centimetres 
nearer  her,  and  without  looking  at  it  or  examining  it  in  detail,  as  was  formerly  her 
habit  when  offered  any  eatable  to  which  she  was  not  accustomed,  she  gobbles  it  up, 
just  as  she  does,  soon  after,  with  the  sugar  also. 

Examination  of  sight,  carried  out  by  the  usual  methods,  reveals  blindness,  or  at 
least  a  very  marked  diminution  of  visual  power,  in  the  left  eye.  With  two  tigs  the 
following  experiment  is  made  : — One  is  brought  a  certain  distance  into  the  outer 
half  of  the  visual  field  of  the  left  eye,  and  is  then  placed  quite  close  to  the  left  upper 
limb,  whilst  the  other  eye  is  covered  with  caoutchouc  ;  under  these  conditions  the 
monkey  makes  no  attempt  to  take  the  fig  although  it  is  quite  within  her  reach.  The 
second  fig  is  now  brought  inwards  from  her  right-hand  side,  and  as  soon  as  it  reaches 
the  right  side  of  the  left  visual  field,  she  immediately  makes  efforts  to  reach  it, 
although  it  is  some  distance  from  her. 

Visual  perception  is  now  tested  in  all  meridians  of  the  visual  field.     Perception 


154  THE  MECHANISM  OF  THE  BRAIN 

is  only  arrived  at  when  the  object  enters  into  the  visual  field  of  the  right  eye,  when 
this  is  left  uncovered,  or  into  the  internal  half  of  that  of  the  left  eye. 

20th  October  1892. — In  all  the  psychic  and  psycho-motor  manifestations  of  this 
monkey  automatism  seems  but  slightly  diminished.  The  circus  movement  towards 
the  right  side  is  well  marked.  When  called  loudly  she  trembles.  After  long 
practice  she  is  beginning  to  attempt  to  give  the  military  salute  when  ordered,  and 
she  shows  a  certain  pleasure  when  caressed.  She  shows  also  an  avidity  to  obtain 
possession  of  any  eatable  shown  to  her,  but  this  is  always  very  transitory  and 
fleeting,  for  her  habitual  state  is  one  of  indifference,  and  soon  she  repeats  her  auto- 
matic, aimless  movements,  evincing  no  interest  in  her  surroundings.  In  new 
positions  she  is  incapable  of  new  adaptations  as  formerly  and,  indeed,  the  majority 
of  these  pass  unobserved  or,  at  any  rate,  make  no  impression.  She  no  longer  plays 
with  the  other  two  monkeys  who  are  her  companions.  She  is  indifferent  if  they  go 
near  her,  or,  if  she  does  dally  with  them  for  a  little,  she  soon  tears  herself  away. 
She  is  no  longer  jealous  if  any  of  them  are  petted.  If  threatened,  she  is  afraid  but 
not  rebellious  ;  she  does  not  react  or  defend  herself  or  threaten  in  turn,  as  she 
formerly  did  with  great  energy.  A  sense  of  indeterminate  and  baseless  fear  seems 
to  overtake  her  whenever  anyone  approaches  her,  or  if  one  breaks  in  upon  her 
automatic  restlessness  with  a  sudden  call,  or  when  any  new  impression  strikes  her. 

The  movements  of  the  limbs  of  the  left  side  are  more  precise,  not  yet  completely 
free,  however,  although  she  makes  use  of  these  limbs  to  take  articles  of  food,  and  as 
her  principal  support  when  making  the  salute,  etc. 

Vision  in  the  left  eye  is  largely  restored,  and  although  it  is  not  easy  to  measure 
it  precisely,  it  is  certain  that  vision  in  the  inner  part  of  the  visual  field  of  the  left 
eye  is  more  distinct. 

She  lived  in  this  state  up  till  the  21st  January  1893. 

2lst  January  1893. — She  maintains  the  same  behaviour  as  in  the  preceding 
months.  She  always  shows  great  restlessness  and  instability.  She  still  exhibits 
a  certain  tendency  to  go  round  from  left  to  right.  She  makes  little  use  of  the  left 
hand.  She  walks  fairly  smartly  so  that  no  paralysis  of  any  kind  is  noticeable. 
In  walking,  however,  she  makes  good  use  also  of  the  left  upper  limb.  All  forms 
of  sensibility  are  well  preserved,  as  previously  recorded,  especially  touch,  hearing 
and  taste.  She  is  to-day  killed  with  chloroform. 

The  left  hemisphere  seems  much  larger  than  the  right.  The  inferior  frontal 
convolution  of  this  hemisphere  is  destroyed  (except  a  small  part  of  the  operculum) 
up  to  its  insertion  into  the  anterior  Rolandic  convolution,  which  is  wholly  spared. 
The  superior  frontal  convolution  is  almost  entirely  spared  up  to  its  anterior  extremity. 
The  right  hemisphere  shows  destruction  of  the  superior  frontal  convolution  up  to 
its  base.  The  extreme  tip  of  this  convolution  is,  however,  spared,  and  it  com- 
municates with  the  rest  of  the  brain  by  a  very  thin  bridge  of  about  2  cm.  in  diameter. 
The  second  frontal  convolution  is  destroyed  to  a  larger  extent.  Of  a  rudimentary 
third  frontal  convolution  there  is  destroyed  only  the  central  part,  the  foot  and 
anterior  extremity  remaining  normal.1 

EXPERIMENT  7. — A  female  monkey,  cinocephalus  porcarius,  fairly  large,  an 
alert  and  lively  animal.  She  often  walks  erect  and  gives  the  salute,  bringing  the 
right  hand  to  the  forehead.  On  careful  examination  no  sensory  or  motor  disorders 
or  defect  of  any  kind  is  detected.  She  is  full  of  curiosity,  perspicacious,  astute, 
familiar  with  and  affectionate  towards  persons  who  have  charge  of  her.  Menstrua- 
tion is  regular.  At  the  period  of  ovulation  she  is  excited  and  rather  shameless, 
judging  from  the  fact  that  she  raises  her  tail  and  exposes  her  genitals. 

20th  May  1893. — Anaesthesia  with  morphine  and  chloroform.     Two  trephine 


1  In  this  brain  a  branch  of  the  pre -frontal  sulcus  running  horizontally  and  at 
right  angles  allows  the  distinction  of  a  third  convolution. 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     155 

openings  are  made  over  the  frontal  lobes,  1  cm.,  or  a  little  more,  in  front  of  the 
Rolandic  line.  Haemorrhage  slight.  The  brain  being  laid  bare,  with  a  sharp  knife 
I  make  curved  incisions  with  convexity  behind,  as  nearly  as  possible  equal  on  both 
sides,  anterior  to  the  feet  of  the  frontal  convolutions  and  just  immediately  in  front 
of  the  pre-frontal  sulcus.  The  faradic  current,  applied  repeatedly  to  various  points 
on  that  portion  of  the  brain  situated  in  front  of  the  incisions,  produces  no  reaction. 
The  observation  is  repeated  under  profound  chloroform-anaesthesia  and  also  under 
the  condition  of  simple  morphinic  lethargy.  With  a  small  scoop  I  remove  all,  or 
almost  all,  those  portions  of  the  frontal  lobes  situated  in  front  of  the  incisions  on 
both  sides.  Haemorrhage  being  controlled  the  surface  of  the  wound  is  washed, 
the  strictest  aseptic  precautions  being  adopted.  The  edges  of  the  dura  mater  are 
sutured,  and  finally  the  cutaneous  wound  is  sutured  and  treated  with  iodoform 
dressing.  The  patient  is  now  placed  and  fixed  on  a  suitable  bed. 

21st  May  1893. — In  a  somnolent  condition  ;  great  reflex  excitability  is  induced 
by  the  slightest  noises.  She  laps  up  a  little  milk  with  great  difficulty,  immersing 
her  nose  in  it.  Temperature  in  vagina,  C.  38:6°. 

22nd  May  1893. — She  continues  in  a  very  low  state  and  sometimes  seems  to  be 
in  a  semi-conscious  condition.  Reflex  excitability  is  very  extreme  so  that  her 
whole  body  shakes  at  the  slightest  noise.  She  is  eating  a  little  more ;  remains  in 
bed  ;  enemata. 

27th  May  1893. — She  is  a  little  more  lively  but  her  head  is  all  swollen  and 
oedematous  as  far  as  the  occiput.  Nevertheless,  the  first  examination  is  now  under- 
taken. Tactile  and  painful  sensibilities  are  exaggerated,  rather  more  on  the  left 
than  on  the  right.  The  slightest  contacts,  even  on  the  points  of  the  hairs,  are 
sufficient  to  provoke  not  only  a  reflex  action  such  as  shaking  of  the  whole  body 
but  also  a  movement  on  the  part  of  the  head  and  eyes,  which  she  turns  towards 
the  part  stimulated.  The  slightest  prick,  or  pinching,  or  pulling  of  the  hairs  in  any 
part  of  the  body,  makes  her  cry  aloud. 

On  bringing  near  the  vibrating  tuning-fork,  from  either  side,  she  is  surprised  by 
the  strange  noise,  moves  her  ears  slightly,  and  turns  her  head  to  the  side  whence 
comes  the  noise,  or  lowers  her  head  as  though  to  get  away  from  the  strange  and 
annoying  sensation.  If  she  is  sleeping,  or,  as  often  happens,  resting  with  her  eyes 
closed,  she  opens  them  if  any  noise  is  made  in  the  room  or  if  the  tuning-fork  is 
approximated  to  one  of  her  ears. 

If  the  hand  or  any  object  whatsoever  is  brought  close  up  to  her  eyes  from  any 
point  in  the  periphery  of  the  visual  fields,  she  winks  the  eyelids  and  withdraws  her 
head  as  though  in  fear.  If  shown  a  cherry,  of  which  she  is  very  fond,  she  fixes  her 
gaze  upon  it;  If  it  is  suspended  to  a  thread  and  allowed  to  fall  from  above,  or 
brought  from  without  inwards,  into  the  visual  field,  she  sees  it,  recognises  it,  and 
with  adequate  and  co-ordinated  movements  tries  to  take  it  between  her  lips  or 
with  her  left  hand. 

Seldom  does  she  get  up  to  walk,  and  then  she  staggers  ;  her  head  is  somewhat 
bent,  there  is  slight  curvature  of  the  trunk,  she  drags  the  right  lower  limb  and 
makes  little  use  of  the  right  hand. 

She  hardly  ever  moves  from  her  couch  and  she  shows  no  interest  in  anything. 
She  trembles  at  the  slightest  noise  and  at  every  touch  even  whilst  being  tended, 
and  then  cries  out  with  manifestations  of  fear,  annoyance  and  anger. 

3rd  June  1893. — The  swelling  of  the  head  has  disappeared  but  the  wound  is 
suppurating  at  one  point,  and  it  is  necessary  to  reopen  it  to  clear  out  a  small 
superficial  abscess  and  to  dress  it  with  every  antiseptic  precaution.  The 
behaviour  of  the  monkey  remains  the  same  as  already  described,  only  she  eats 
more  and  stands  more  erectly  on  her  legs,  and  can  walk,  although  with  some 
uncertainty,  for  she  drags  the  right  lower  limb,  which  seems  almost  completely 
paralysed. 

1th  June  1893. — Suppuration  has  ceased.     The  wound   is  granulating  and  is 


THE  MECHANISM  OF  THE  BRAIN 

rnig  dressed  with  sublimate  and  iodoform.  There  is  no  fever  nor  has  there  been 
any  since  the  first  few  days  after  the  operation.  The  behaviour  of  the  monkey  is 
rather  surprising  and  altogether  new.  She  remains  in  any  position  in  which  she  is 
placed  and  shows  no  curiosity  or  interest  in  what  is  happening  around  her.  For 
hours  together  she  sits  with  head  bent  or  remains  curled  up,  often  asleep.  If  any 
noise  is  made  her  whole  body  trembles  and  often  she  gives  a  cry,  raises  her  head, 
and  looks  around,  only  to  fall  again  into  her  former  position.  The  same  scene 
occurs  three  or  four  times  in  succession,  as  the  noise  is  repeated. 

Nothing  excites  her  curiosity  or  induces  her  to  move  except  the  sight  of  some 
favourite  fruit,  such  as  a  cherry,  which  is  thrown  down  a  short  distance  in  front 
of  her.  In  this  case  she  rises  and  runs  forward  to  take  it.  If,  however,  the  cherry 
is  thrown  rather  farther  away,  she  does  not  run  after  it,  and  it  is  difficult  to  say  if 
it  is  owing  to  the  fact  that  she  does  not  see  it  or  if  it  is  due  to  inertia  or  laziness 
or  indifference.  She  scratches  herself  now  here  now  there,  especially  on  the  left 
side,  but  does  not  search  for  parasites  with  that  promptitude  and  facility  which 
were  apparent  prior  to  the  operation.  If  one  wishes  to  remove  her  from  the  position 
she  occupies  she  resists  and  if  she  can  lay  hold  of  anything  she  clings  to  it  obstinately; 
If  taken  by  the  neck  and  forcibly  driven  from  her  position,  she  walks  a  certain 
distance,  rubbing  by  preference  along  the  wall  till  she  comes  to  a  corner,  where  she 
stops,  remaining  there  for  a  considerable  time.  If  called  loudly  she  raises  her  head 
in  a  listening  and  attentive  attitude,  then  sinks  back  with  the  head  bent  forward, 
and  in  this  position  saliva  frequently  runs  from  her  mouth.  If  she  wishes  to  empty 
her  bladder  or  bowels  she  does  not  move  off  to  some  other  spot  as  she  used  to  do 
but  evacuates  them  wherever  she  may  happen  to  be,  wetting  and  messing  herself 
like  a  stupid  dement. 

She  meets  another  female  monkey  of  the  same  species.  This  animal  is  menstruat- 
ing and  in  a  highly  erotic  condition.  Monkey  No.  1  stops  automatically  but 
remains  quite  indifferent  to  the  many  caresses  bestowed  on  her  by  monkey 
No.  2.  The  latter  exposes  her  genitals,  touches  the  other's  nipples,  and  uses  her 
hands,  in  a  lascivious  manner.  Monkey  No.  1  stands  like  an  automaton,  be- 
traying no  sign  of  instinct  aroused,  nor  the  slightest  community  of  interest  or 
feeling  with  the  other  animal. 

Meanwhile  a  noise  causes  her  to  shake  and  to  show  fear.  On  threatening  her 
with  a  stick  she  becomes  much  more  terrified  than  the  other  monkey,  which 
evidently  notices  the  sham  attitude  of  the  experimenter,  and  so  remains  indifferent 
to  those  same  threats  which  frighten  monkey  No.  1. 

Fruits,  sugar,  or  other  eatables  of  which  she  is  fond  excite  her  rather  more,  and 
so  she  darts  forwards  with  a  certain  avidity  to  get  hold  of  cherries  and  pieces  of 
sugar,  in  doing  which  she  shows  no  discrimination.  No  more  certain  proof  of  her 
loss  in  discrimination  can  be  furnished  than  her  conduct  in  comparison  with  the 
other  monkey.  I  open  two  cherries,  put  a  drop  of  solution  of  quinine  into  both 
of  them  and  give  one  to  each  monkey.  The  healthy  animal,  after  a  few  moments 
of  examination,  rejects  it  from  her  inouth  with  a  movement  of  impatience,  makes 
faces,  looks  at  me  in  a  disdainful  manner,  cleans  her  tongue  several  times  with  the 
back  of  her  hand,  then  rubs  and  squashes  that  deceptive  cherry  on  the  ground  with 
her  hand,  till  nothing  is  left  of  it.  Monkey  No.  1,  however,  masticates  her 
cherry,  but  stops  after  a  time  and  commences  to  pour  out  a  great  quantity  of  saliva 
from  her  mouth ;  for  some  time  she  cannot  decide  whether  to  swallow  the  cherry 
or  to  spit  it  out,  but  finally  ends  by  swallowing  it.  I  offer  them  other  good  cherries, 
which  are  eaten  with  great  relish  by  both  of  them.  Afterwards  I  give  each  of  them 
a  cherry  that  has  been  dipped  in  solution  of  quinine.  The  healthy  monkey  puts 
hers  in  her  mouth  but  immediately  rejects  it  and,  as  she  throws  it  away,  makes 
faces  and  exhibits  anger.  Shortly  afterwards,  seeing  it  lying  sound  and  whole, 
she  takes  it  up  again,  scrutinises  it  carefully,  opens  it,  cautiously  eats  the  pulp 
and  throws  away  the  skin.  Monkey  No.  1  keeps  her  cherry  in  her  mouth 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     157 

for  a  while,  is  undecided  whether  to  masticate  it  or  reject  it,  and  after  a  certain  time, 
during  which  much  saliva  has  poured  from  her  mouth,  ends  by  swallowing  it. 

To  the  healthy  monkey  I  now  offer  a  piece  of  sugar,  and  shortly  afterwards 
a  piece  of  chalk  of  the  same  colour  and  appearance,  which  I  take  from  amongst 
other  pieces  of  sugar  in  my  hand.  When  I  throw  in  front  of  her  the  piece  of  chalk 
she  takes  it  up,  examines  it  carefully,  raises  it  to  her  nostrils,  smells  it  and,  without 
even  tasting  it,  throws  it  away.  After  she  has  eaten  some  cherries^  I  offer  her  a 
piece  of  sealing-wax  of  the  same  shape  and  colour  as  these.  She  takes  it,  examines 
it,  re-examines  it,  turns  it  round  in  her  fingers  as  though  surprised,  smells  it,  lets 
it  fall  on  the  ground  as  though  to  test  it  by  the  sound  and  ends  by  squashing  it  on 
the  floor  and  abandoning  it.  These  experiments  are  repeated  with  the  monkey 
which  has  been  operated  upon  and  in  each  case  she  shows  a  surprising  critical 
defect,  in  this  respect,  that  without  any  discrimination  she  takes  the  piece  of  chalk 
just  as  she  took  the  piece  of  sugar,  masticates  and  swallows  it.  Later,  on  repeating 
the  experiment  with  the  cherries,  she  again  gives  proof  of  her  deficiency,  inasmuch 
as  she  takes  the  piece  of  sealing-wax,  puts  it  in  her  mouth  although  it  is  different 
in  shape,  masticates  it,  and  only  by  dint  of  cajolery  are  we  able  to  extract  it  from 
her  mouth. 

20th  June  1893. — No  change  in  her  condition. 

15th  July  1893. — We  have  kept  this  monkey  under  observation  with  the  object 
of  studying  better  her  characteristic  tendencies,  instincts  and  intelligence  in  com- 
parison with  the  known  condition  of  these  prior  to  operation.  Without  the  slightest 
doubt  her  behaviour  is  altered  and  her  physiognomy  more  stupid.  She  is  torpid. 
Her  glance  is  rather  uncertain  and  betrays  no  flash  of  roguery  nor  does  it  light 
up  with  curiosity.  The  instinct  of  sociability  seems  abolished.  Fear  and  terror 
characterise  the  mental  state  of  this  animal.  She  is  perturbed  and  afraid,  cries 
out,  and  grinds  her  teeth  at  every  feigned  threat  and  every  painful  stimulus,  but 
she  never  reacts  in  an  aggressive  sense.  For  some  time  past  she  has  been  rather 
restless.  When  in  a  large  room  with  all  exits  closed,  she  crosses  backwards  and 
forwards,  always  in  the  same  directions,  without  stopping  near  any  object  or  person 
in  the  room.  There  is  an  evident  absence  of  objective  in  her  movements  ;  or,  if 
she  does  give  some  indication  of  objective,  it  is  soon  forgotten,  is  transitory  and 
elusive.  Thus,  e.g.,  she  sometimes  runs  towards  the  door,  stops  near  it,  then 
turns  back  and  retraces  her  steps,  running  towards  the  opposite  door,  and  so  on 
many  times  in  succession. 

She  no  longer  shows  any  sentiment  either  of  affection  or  gratitude  towards 
those  persons  to  whom  she  was  formerly  much  attached,  whose  legs  she  used  to 
embrace  and  with  whom  she  used  to  chatter,  as  is  the  way  of  these  animals.  Indeed, 
it  seems  as  though  she  were  absolutely  indifferent  to  them  although  they  bestow 
no  less  care  and  kindness  on  her  than  before.  There  is  not  merely  an  indifference, 
but  a  ready  reaction  characterised  by  fear  every  time  anyone  comes  near  her,  even 
when  one  shows  a  desire  to  pet  her.  If  she  sees  one  of  the  attendants  carrying  her 
bowl  or  a  piece  of  fruit  in  his  hand,  only  then  does  she  approach  him,  giving  him 
no  time  to  offer  the  food,  but  tearing  from  his  hand,  without  any  restraint,  whatever 
has  awakened  her  violent  appetite.  It  is  .no  longer  possible  for  her  to  be  petted 
by  me  or  my  attendants  at  the  Institute,  with  whom  she  was  formerly  very  familiar. 
She  is  no  longer  sociable  with  the  other  monkeys,  nor  does  she  ever  play  with  them. 
She  shows  no  resource  in  front  of  small  difficulties,  no  new  adaptations.  She  has 
learned  nothing  new  and  has  regained  little  or  nothing  of  what  she  lost.  She 
gathers  up  and  puts  in  her  mouth  anything  she  comes  across,  but  is  less  filthy  than 
formerly. 

The  sexual  instinct  seems  to  have  returned,  but  the  menstrual  periods  are  less 
regular  and  the  flow  less  abundant.  Sometimes  she  displays  an  impulsive  cruelty 
that  is  foreign  to  her  kind.  One  day,  whilst  she  was  menstruating,  another  female 
cynocephalus  came  near  her.  She  at  once  manifested  her  desire  by  lifting  up  her 


158  THE  MECHANISM  OF  THE  BRAIN 

tail  and  exposing  the  vulva  ;  but  finding  the  other  unable  to  satisfy  it  she  attacked 
her  companion  so  ferociously  that  she  would  have  killed  her  had  it  not  been  for  the 
presence  of  the  keeper  who,  armed  with  a  stick,  drove  her  off. 

She  suffers  from  a  psycho-motor  tic  which  has  first  appeared  during  these  past 
few  days.  Every  ten  or  fifteen  minutes,  whilst  walking,  she  suddenly  sits  down 
and,  placing  the  foot  on  the  hip,  bites  the  right  buttock  (sometimes  also  the  left). 
Occasionally  she  proceeds  to  bite  also  one  heel,  then  the  other,  after  which  she 
quietly  resumes  her  walk.  In  the  regions  which  she  bites  there  is  no  local  factor 
to  be  detected  which  may  explain  these  movements,  which  are  always  identical, 
stereotyped,  almost  rhythmical.  It  is  possible  that  some  abnormal  sensation  has 
first  of  all  given  rise  to  them,  in  an  effort  to  remove  a  source  of  irritation,  and  the 
movements  have  afterwards  remained  fixed,  obeying  the  law  of  automatism,  and 
withdrawn  from  all  control. 

15th  August  1893. — The  mental  state  of  this  animal  remains  unchanged.  Her 
movements  have  a  stereotyped  character,  but  are  otherwise  perfect.  It  has  not 
been  possible  for  her  to  acquire  any  new  adaptation.  She  walks  up  and  down,  sits 
and  rests  from  time  to  time,  and  searches  for  parasites  all  over  the  body.  She 
bestirs  herself  a  little  when  she  sees  her  customary  bowl  of  food,  otherwise  she  is 
indifferent  to  everyone  and  everything.  She  often  puts  the  parasites  in  her  mouth, 
a  thing  which  she  never  did  in  the  past.  Occasionally  she  collects  and  eats  dried 
flowers  and  leaves.  Menstruation  is  still  irregular.  Since  the  brutal  sexual  episode 
referred  to  in  the  previous  note  she  has  not  again  exposed  herself  either  before  or 
during  menstruation,  nor  has  she  expressed  any  desire  or  invitation  by  lascivious 
chattering  or  gesture  as  she  did  on  that  occasion.  Indeed  her  voice  has  not  been 
heard  since  she  underwent  operation. 

Her  movements  are  precise,  and  there  is  no  sign  of  any  sensory  disturbance  or 
defect.  On  that  point  there  is  no  doubt  whatever.  Discrimination,  however,  and 
that  higher  co-ordination  of  sensory  factors  which  gives  rise  to  more  complex 
psychic  manifestations,  and  to  actions  more  suited  to  the  conservation  of  the  in- 
dividual and  of  the  species,  are  reduced  to  quite  rudimentary  proportions.  For 
example,  we  give  her  a  sweet ;  she  takes  it  and  eats  it  with  relish.  Then  we  offer 
her  a  piece  of  chalk.  This  time  she  notices  that  i.t  is  not  a  sweet,  but  puts  it  in  her 
mouth,  breaks  it  with  her  teeth,  and  reduces  it  to  a  great  many  small  pieces,  which 
she  spits  out  on  the  floor.  Then  with  each  fragment  she  commences  a  series  of 
stereotyped  movements.  She  takes  up  one  fragment,  lays  it  down,  takes  it  up 
again,  raises  it  to  her  mouth,  replaces  it  on  the  ground,  takes  it  up  again  and  eats  it 
greedily,  and  so  on  with  the  second,  third,  tenth,  until  not  one  of  the  smallest  frag- 
ments of  that  piece  of  chalk  remains  on  the  ground.  The  white  colour  of  these 
fragments  and  their  resemblance  to  those  of  the  sweet  have  been  her  guide,  and 
have  prevailed  over  her  sense  of  taste.  Her  rudimentary  power  of  arrest  has 
promptly  been  overcome  by  the  visual  image  of  the  fragment  alone.  There  has 
been  no  intervention  of  other  factors  for  the  judgment  of  identification,  similarity, 
dissimilarity  or  analogy.  She  is  certainly  capable  of  experiencing  single  sensations, 
but  she  cannot  co-ordinate  the  individual  representations  so  as  to  arrive  at  more 
complex  movements  and  judgments  of  a  higher  order.  As  a  matter  of  fact,  a  normal 
monkey  either  takes  the  piece  of  chalk,  looks  at  it,  examines  it,  smells  it,  and  dis- 
cards it,  or,  if  it  resembles  a  sweet  very  closely,  puts  it  in  her  mouth,  but  spits  it  out 
immediately  it  is  broken,  and  pays  no  more  attention  to  the  fragments.  In  this 
case  the  judgment  of  comparison  is  sufficiently  sure,  and  the  memory  of  it  suffi- 
ciently lasting  to  spare  her  from  the  sequel  of  movements  exhibited  by  the  other 
monkey,  in  whose  case  there  prevails  a  more  elementary  representation  which  can 
only  give  rise  to  movements  that  are  inadequate  and  impulsive  in  character.  In 
the  monkey  operated  upon,  the  utilisation  of  past  experience  is  absolutely  wanting. 
23rd  August  1893. — Her  condition  being  stationary,  and  the  Congress  at  which 
it  was  intended  to  demonstrate  this  monkey  having  been  postponed,  it  has  been 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     159 

decided  to  proceed  to  the  autopsy.  After  anaesthesia  by  chloroform,  the  right  hemi- 
sphere is  laid  bare.  The  existence  of  all  the  motor  centres  of  the  limbs  and  of  the 
face  is  ascertained  by  electric  excitation,  and  afterwards  the  animal  is  killed  with 
chloroform. 

EXPERIMENT  8. — 2nd  August  1893. — A  young  female  monkey  of  the  family  of 
cinocephalidoe  (higher  Cebus),  which  has  been  tended  with  care  for  some  time  in  the 
Institute,  and  has  become  fairly  domesticated.  She  has  had  her  first  two  menstrual 
periods.  She  is  good-natured,  affectionate  towards  me,  and  the  attendants  of  the 
Institute,  to  all  of  whom  she  shows  grateful  recognition.  She  is  docile,  obedient, 
lively  and  full  of  curiosity. 

I  have  had  this  monkey  under  observation  for  a  long  time  and  have  kept  her 
near  the  entrance  to  my  laboratory  so  that  I  might  have  her  under  my  eyes  as  much 
as  possible.  Along  with  my  assistants  I  have  been  able  to  make  many  observations 
and  experiments  upon  her,  to  some  of  which  reference  is  now  made. 

On  certain  occasions  she  has  been  given  a  small  bottle  with  a  narrow  neck,  full  of 
water  and  sugar.  She  has  taken  it  in  both  hands,  has  drunk  the  contents  with 
relish,  and  then  exercised  her  ingenuity  as  best  she  could  in  order  to  get  the  sugar 
lying  at  the  bottom  of  the  bottle.  First  she  introduced  one  or  two  fingers  into  the 
bottle  as  far  as  she  could,  then  withdrew  and  licked  them.  Next  she  thrust  her 
tongue  into  the  bottle  and  licked  the  inside.  After  having  done  this  several  times 
she  seemed  to  become  irritated  because  unable  to  succeed  in  her  design,  so  she 
squeezed  the  bottle  between  her  hands  and  against  her  chest  in  an  attempt  to  break 
it.  Convinced  at  length  that  in  no  other  way  could  she  satisfy  her  eager  appetite, 
she  forcibly  threw  it  on  the  ground  so  as  to  break  it,  then  eagerly  licked  the  sugar 
from  the  fragments  of  the  bottom  of  the  bottle. 

She  recognised  perfectly  the  persons  who  were  in  the  habit  of  giving  her  any- 
thing, and,  in  acknowledgment,  she  would  sit  on  her  ischial  tuberosities,  stretch  out 
her  hand,  seek  to  grasp  their  clothing,  and  then  go  through  some  movements  as 
though  seeking  for  lice,  to  the  accompaniment  of  a  special  vocal  sound,  which,  by  its 
constant  repetition  in  presence  of  persons  with  whom  she  was  friendly,  might  almost 
be  characterised  as  a  manifestation  of  contentment,  friendliness  and  devotion.  If 
anyone  bent  down  so  as  to  bring  his  head  within  reach  of  her  hands,  she  acted  in  a 
similar  way,  apparently  seeking  for  insects. 

If  anyone  poked  at  .her  with  a  stick,  or  made  as  though  to  strike  her,  or  turned  a 
jet  of  water  on  her,  she  became  irritated,  stood  on  her  hind  legs,  leapt  forwards, .con- 
tracted her  lips  strongly,  displayed  and  ground  her  teeth,  gave  a  loud  cry  and,  being 
unable  to  reach  the  person  molesting  her  because  of  her  chain,  she  hurled  at  him  or 
thrust  towards  him  anything  she  eould  lay  hold  of. 

On  several  occasions  we  had  occasion  to  lunch  in  the  laboratory,  and  were  in  the 
habit  of  throwing  her  something  to  eat,  as  she  was  tied  up  opposite  the  entrance  to 
the  laboratory.  If  it  happened  that  by  chance  she  was  tied  up  a  little  farther  away 
than  usual,  so  that  she  could  not  be  seen  by  us,  and  she  knew  that  we  were  at  lunch, 
we  could  hear  her  shaking  her  chain  noisily  and  emitting  her  usual  grunts,  as 
though  determined  to  make  us  aware  of  her  presence.  If  we  pretended  not  to  hear 
her,  she  became  irritated  and  threw  her  milk-tin,  which  was  lying  near,  or  any  other 
article  she  could  get  hold  of,  with  violence  towards  the  door  of  the  laboratory. 

She  was  very  fond  of  cigarette  ends,  and  if  any,  still  alight,  were  thrown  near  her 
she  rubbed  them  on  the  ground  with  both  hands  so  as  to  extinguish  them,  and  then 
ate  them.  Again,  if  anything  was  thrown  on  the  ground  in  front  of  her  which  she 
could  not  manage  to  grasp  with  her  outstretched  fore  limbs,  she  stretched  out  her 
body  and  attempted  to  lay  hold  of  it  with  the  extremities  of  the  hind  limbs,  using 
these  like  forceps. 

When  offered  a  piece  of  coffee-ice  she  did  not  grasp  it  in  her  hands,  but  took  it 
with  her  tongue  and  lips,  apparently  to  avoid  the  unpleasant  sensation  of  cold  on 


160  THE  MECHANISM  OF  THE  BRAIN 

the  finger-tips,  or  to  prevent  the  ice  melting.  If,  however,  she  was  given  a  glass 
with  some  coffee-ice  in  it  she  took  it  in  her  hands,  as  any  person  would  do. 

During  menstruation  her  genitals  became  so  greatly  swollen  that  the  tension  of 
the  parts  must  have  caused  her  great  pain  and  discomfort.  She  then  assumed  such 
positions  as  afforded  her  some  measure  of  relief,  at  the  same  time  applying  some 
pressure  to  the  parts  with  her  hands. 

She  was  greatly  averse  to  the  presence  of  women,  and  if  by  chance  she  saw  one, 
she  was  apt  to  throw  at  her  anything  that  lay  within  her  reach  (jealousy  ?). 

The  experiment  with  the  sugar  and  the  chalk  was  repeated  on  several  occasions 
with  this  monkey.  She  ate  the  sugar,  but,  recognising  the  chalk,  either  from  its 
form  or  its  tactile  impression,  threw  it  away. 

If  she  saw  anyone  washing  his  hands  with  soap  she  at  once  imitated  his 
movements. 

She  nourished  no  hatred  or  rancour  towards  anyone  who  molested  her.  Indeed, 
if  anyone  who  had  irritated  her  afterwards  came  up  to  her  and  petted  her,  she  very 
soon  entered  into  a  treaty  of  peace  with  him. 

If  anyone  began  by  playing  with  her  and  then  commenced  to  molest  her,  one 
could  notice  the  gradual  passage  of  her  voice  from  the  sound  before  mentioned  to  a 
very  piercing  cry. 

She  manifested  very  great  affection  towards  another  monkey,  destined  for 
experiment,  and  once  when  she  happened  to  be  near  her  embraced  her  in  a  veritable 
transport  of  joy. 

One  day  I  gave  her  a  plum,  a  fruit  of  which  she  was  very  fond,  and  she  ate  it 
eagerly.  On  another  occasion  I  injected  a  little  solution  of  quinine  into  a  plum  by 
means  of  a  syringe,  and  gave  it  to  her.  As  soon  as  she  put  her  teeth  into  it,  she  drew 
back  her  head,  horrified.  She  examined  it  carefully  from  every  point  of  view,  then, 
as  though  her  mind  were  made  up,  nervously  detached  all  the  pulp  with  her  fingers^ 
broke  the  stone,  ate  the  kernel  and  threw  away  all  the  rest.  What  she  thr?w  away, 
however,  she  picked  up  from  time  to  time  in  her  greedy  desire  to  eat,  and  after 
having  examined  it  minutely,  and  smelt  it,  and  cautiously  tasted  it,  threw  it  away 
again, 

Memory. — A  long  time  afterwards  I  again  gave  her  some  plums,  which  she  ate 
very  circumspectly  and  only  after  she  had  examined  them  minutely,  and  smelt 
them,  and  tested  them  on  the  tip  of  her  tongue. 

The  left  anterior  brain  is  now  exposed  through  a  large  opening.  On  electric 
excitation,  employing  a  Du  Bois  Reymond  sledge,  no  excitable  point  is  detected  in 
front  of  a  and  b  (these  are  two  points  of  rendezvous,  one  above  and  one  below,  in  a 
slightly  curved  line  situated  in  front  of  the  excitable  area  of  the  limbs).  Excitation 
of  a  provokes  movements  of  the  muscles  of  the  trunk  and  pelvis  which  need  not  be 
further  referred  to.  Excitation  in  b  provokes  combined  movements  upwards  and 
forwards  of  the  pavilion  of  the  ear,  widening  of  the  palpebral  fissure,  with  elevation 
of  the  upper  eyelid,  and  dilatation  of  the  pupils  (more  marked  on  the  same  side). 
This  excitation  is  repeated  several  times,  always  with  the  same  result.  On  slightly 
increasing  the  strength  of  the  current  or  on  displacing  the  electrodes  one  or  two 
millimetres  backwards,  movements  of  the  hand  (extension  of  the  fingers  chiefly) 
are  obtained. 

With  a  sharp  curved  blade  I  make  a  deep  incision  into  the  frontal  lobe  in  front 
of  the  points  a  and  b,  which  I  just  graze  but  leave  undamaged.  I  remove  about  six 
grammes  of  brain  tissue.  Haemorrhage  scanty.  The  surface  of  the  wound  is  now 
washed  and  all  blood  and  detritus  removed.  Rigorous  antiseptic  precautions. 
Suture  of  the  edges  of  the  dura  mater  and  of  the  overlying  soft  parts. 

3rd  August  1893. — She  is  dosing  almost  the  whole  day.  She  sits  on  her  hind 
quarters  and  does  not  lie  down.  No  deviation  of  the  head  or  eyes.  Makes  use  of 
her  hands,  preferably  the  left.  Goes  from  one  point  to  another  in  the  large  cage 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     161 

without  showing  any  disturbance  of  gait.  She  takes  a  little  milk.  The  head  is 
erect  and  mobile. 

4th  August  1893. — Same  condition  ;  is  sick  once. 

1th  August  1893. — Has  quite  revived  from  the  operation.  The  edges  of  the 
wound  are  adherent,  and  healing  by  first  intention  is  almost  complete. 

Apart  from  a  certain  degree  of  fear,  and  hemianopsia  of  the  outer  half  of  the  right 
visual  field  (which  can  only  be  detected  by  minute  and  careful  examination),  this 
monkey  now  seems  completely  restored  to  her  former  condition.  To  look  at  her 
one  would  hardly  imagine  that  she  had  lost  a  part  of  her  brain. 

She  walks  perfectly  and  has  never  shown  any  circus  movement.  She  can  move 
her  head  and  trunk  in  all  directions  without  any  difficulty  and  without  any  sign  of 
preponderance  of  one  side  over  the  other.  She  can  move  about  with  the  same 
promptitude  and  with  the  same  ability  as  before. 

When  taken  unawares,  contacts  in  the  region  of  the  face  and  the  ear  provoke 
the  same  degree  of  notice  on  either  side. 

Punctures  with  a  very  fine  needle  produce  lively  reactions,  in  the  form  of  cries, 
agitation  and  flight,  especially  when  taken  by  surprise. 

On  obstructing  vision  by  the  application  of  sub-palpebral  eye-shades  of  caout- 
chouc, after  previous  application  of  cocaine,  she  displays  some  excitement  and 
uncertainty  for  a  time,  but  soon  afterwards  shows,  by  the  precision  of  her  move- 
ments, that  she  possesses  a  normal  muscular  sense.  If,  e.g.,  a  peach  is  placed 
within  her  reach  she  immediately  grasps  it,  bites  it,  peels  it,  and  puts  pieces  of  it 
in  her  mouth  with  either  hand,  always  with  precise  arid  certain  movements. 

She  hears  the  sound  of  the  tuning-fork  at  an  equal  distance  on  either  side  and 
is  afraid  of  it  when  it  is  brought  up  to  the  ear. 

A  methodical  examination  of  the  senses  of  taste  and  smell  has  not  been 
carried  out,  but  it  has  been  observed  that  she  shows  a  preference  for  peaches 
rather  than  pears,  for  the  latter  rather  than  bread,  and  for  sweets  more  than 
pears. 

From  the  day  of  the  operation  she  has  presented  a  defect  of  vision  in  the  opposite 
eye.  An  assistant  holds  her  in  his  arm  on  the  table.  Another  assistant  stands 
opposite  and  attracts  her  attention  with  a  peach  or  a  pear.  Standing  behind,  I 
bring  a  piece  of  peach  to  within  10  to  25  cm.  of  one  or  other  eye,  moving  it  from 
without  or  above,  so  as  to  test  the  various  ocular  meridians.  When  the  piece  of 
peach,  proceeding  from  without  and  behind,  arrives  at  a  point  corresponding  to 
the  external  angle  of  the  left  eye,  she  immedianely  notices  it,  turns  her  head  and  eyes 
towards  it  and,  sometimes,  with  a  rapid  movement  of  the  hand,  seizes  it  and  puts 
it  in  her  mouth.  When  the  same  experiment  is  repeated  at  the  external  angle  of 
the  right  eye,  it  is  always  necessary  to  advance  the  piece  of  peach  much  farther 
forward,  to  a  point  corresponding  to  the  median  vertical  axis  of  the  eye,  so  that  she 
may  notice  it  and  behave  in  a  similar  fashion. 

12th  August  1893. — The  examination  is  repeated  and  a  certain  difference  between 
the  two  eyes  is  still  noticeable,  although  it  is  not  so  marked  or  so  definite  as  before. 
With  the  right  eye  the  monkey  notices  anything  but  does  not  recognise  it  until  it 
has  arrived  almost  at  the  median  line  and  then  she  grasps  it  with  rapid  and  certain 
movement ;  whilst  as  soon  as  any  object  enters  into  the  visual  field  at  the  external 
angle  of  the  other  eye,  she  immediately  recognises  it  and  seeks  to  take  hold  of  it 
with  rapid  and  precise  movements. 

llth  September  1893. — She  is  always  lively,  agile,  quick  and  observant.  She 
unties  a  cord  which  secures  the  door  of  the  cage,  draws  out  an  iron  pin,  then 
makes  her  exit,  without  going  far  from  the  establishment. 

She  is  very  fond  of  tobacco.  I  throw  in  front  of  her  half  a  cigar  still  alight. 
She  goes  to  pick  it  up  with  her  left  hand,  which  she  burns,  withdrawing  it  in  great 
haste  and  then  licking  the  fingers  which  are  sore. 

She  waits  for  a  little,  picks  up  the  cigar  again  very  cautiously,  taking  hold  of 
L 


162  THE  MECHANISM  OF  THE  BKAIN 

the  end  that  has  not  been  lit,  examines  it,  smells  it,  strips  the  leaves  off  it,  and  eats 
them  one  by  one. 

She  remains  under  observation  until  January  1894,  showing  no  change,  apart 
from  the  fact  that  she  has  become  rather  more  irritable. 

31st  January  1894. — Anaesthesia  by  morphine  and  chloroform.  The  anterior 
part  of  the  right  hemisphere  is  now  laid  bare.  The  ascending  frontal  and  posterior 
part  of  the  first  frontal  convolution  remain  unexposed.  No  movements  of  any  kind 
are  provoked  by  faradic  excitation  of  the  cortical  surface  lying  in  front  of  the  feet 
of  the  frontal  convolutions,  except  in  the  inferior,  opercular,  part  of  the  second 
convolution,  where,  in  front  of  the  facial  centre  (contraction  of  the  muscles  of  the 
lower  half  of  the  face),  one  can  determine  a  vertical  rectangular  area,  extending 
upwards  and  embracing  all  the  second  frontal  convolution,  where  excitation  con- 
stantly provokes  slight  widening  of  the  palpebral  fissures,  slight  raising  of  the 
eyebrows,  and  dilatation  of  the  pupils,  more  marked  on  the  side  opposite  to  the 
excited  hemisphere.  At  the  foot  of  the  first  convolution  and  also  a  little  further 
forward,  excitation  produces  movement  of  the  head  and  eyes  to  the  opposite  side. 
It  has  not  been  possible  to  induce  any  other  manifestation. 

Repeated  electric  excitation  of  the  pupillary  centre  induces  a  more  prolonged 
dilatation  of  the  opposite  pupil,  lasting  about  ten  minutes. 

I  now  incise  the  brain  immediately  in  front  of  the  centre  for  the  face  and  behind 
the  centre  for  the  dilator  iridis,  I  remove  as  much  as  possible  of  what  remains  of 
the  frontal  lobe  in  front  of  the  incision,  only  the  posterior  third  of  the  first  convolution 
being  spared. 

Slight  haemorrhage.  Lavage  of  the  resulting  cavity  with  sublimate  solution 
(1  in  2000).  Aseptic  dressing. 

After  the  operation  the  animal  remains  depressed  and  somnolent  for  several 
hours,  but  when  called  opens  her  eyes.  No  vomiting,  no  fever. 

2nd  February  1894. — She  remains  in  a  sitting  position  with  the  head  bent,  the 
eyes  closed,  and  drowsy.  When  called,  she  raises  her  head,  slowly  opens  her  eyes, 
looks  around,  then  resumes  her  former  position.  If  any  part  of  her  body  is  touched 
she  wakens  up,  sometimes  giving  a  sudden  jump  or  emitting  a  cry,  but  does  not 
run  off  or  show  any  sign  of  fear. 

Driven  from  her  couch  and  left  at  liberty  in  the  room,  she  paces  the  floor  in 
every  direction,  with  measured  steps.  No  deviation  of  the  trunk  can  be  detected, 
nor  paralysis,  except  in  the  left  side  of  the  face  (lower  half),  where  it  only  becomes 
evident  when  she  grinds  her  teeth  or  cries  out. 

Qth  and  14:th  February  1894. — The  records  of  these  two  days  are  given  as  one, 
because  identical. 

Facial  paresis  on  the  left  (opposite)  side  continues.  It  is  less  evident  than 
before,  but  there  is  no  doubt  as  to  its  existence.  In  walking,  the  lower  part  of  the 
trunk  is  seen  to  be  slightly  arched.  She  turns  to  right  and  left,  runs  and  gallops 
about,  curls  herself  up  if  frightened,  and  betrays  no  trace  of  paralysis.  There  is 
no  difference  in  the  two  sides,  but  she  has  lost  the  elasticity,  the  suppleness,  and  the 
darting,  jumping  movements  so  characteristic  of  monkeys.  She  has  gained  in 
weight  and  is  inclined  to  fall  and  be  awkward  in  her  movements  when  chased.  She 
makes  use  preferably  of  the  left  hand  but  also  grasps  objects  with  the  right,  and 
does  so  with  fair  precision  though  with  less  resolution  and  certainty  than  with  the 
left  hand.  She  can  raise  and  lower  her  head  and  turn  it  to  right  and  to  left.  There 
is  no  trace  of  paralysis  in  the  muscles  of  the  neck  and  back  of  the  head.  She  takes 
her  food  very  well  and  eats  it  with  relish,  swallows  well,  and  calls  out  as  before. 

Tactile  sensibility  is  well  preserved.  If,  taking  her  unawares,  we  touch  any 
part  of  the  body,  she  notices  the  contact  at  once,  withdraws  the  limb  or  shakes 
herself,  or  cries  out,  or  turns  her  head  and  eyes  towards  the  side  touched.  Feeling 
is  less  acute  on  the  left  ear,  as  one  may  judge  from  the  fact  that  on  touching  or 
tickling  that  region  she  does  not  move  the  ear  nor  shake  herself,  as  always  happens 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     163 

in  the  case  of  the  right  ear.  She  scratches  herself  and  seeks  for  parasites  equally 
readily  on  either  side,  using  both  hands  with  fairly  precise  movements.  At  the 
same  time,  it  is  evident  that  the  muscular  sense  is  well  preserved,  for  no  sign  of 
ataxia  is  evident  in  her  gait,  or  in  movements  of  prehension,  or  even  in  more  delicate 
actions.  The  right  eye  being  covered  (same  side  as  recent  extirpation)  the  monkey 
walks  and  runs  about  without  ever  knocking  against  any  of  the  obstacles  in  her 
path,  such  as  a  table,  chairs,  a  stick,  etc.  She  avoids  them  all  with  precision. 

If,  however,  she  is  now  held  at  rest  on  a  table,  and  a  piece  of  sugar  suspended  by 
a  thread  is  brought  from  without  inwards  into  the  left  visual  field,  she  does  not 
perceive  it  until  it  reaches  the  line  of  the  visual  axis,  and  then  only  does  she  grasp 
it  with  a  rapid  movement  of  the  right  or  of  the  left  hand,  snapping  it  up  and  putting 
it  into  her  mouth.  This  experiment  on  several  repetitions  has  always  given  the 
same  result.  It  is  different  in  the  case  of  the  right  eye,  when  the  left  eye  is  com- 
pletely covered.  In  this  case,  when  the  piece  of  sugar  passes  beyond  the  external 
physiological  limit  of  the  visual  field  she  turns  her  gaze  on  it,  makes  a  grab  at  it, 
and,  if  one  does  not  promptly  remove  it,  takes  hold  of  it.  There  is  no  marked 
difference  between  the  two  eyes  in  the  extent  of  the  visual  fields  upwards  and 
downwards.  Owing  to  the  excited  condition  of  the  animal  it  has  not  been  possible 
to  examine  the  internal  part  of  the  right  visual  field. 

Intelligence. — Stupid  in  her  general  attitude  ;  changed  and  expressionless  in  her 
physiognomy.  Like  the  previous  monkey,  she  runs  from  one  end  of  the  room  to  the 
other  in  an  incoherent  manner ;  arrived  at  one  wall,  she  stops  a  little,  turns  back 
and  goes  towards  the  opposite  corner ;  half-way  she  sees  a  spot  on  the  wall  where 
plaster  has  come  off,  she  goes  and  sits  opposite  it,  and  with  her  teeth  or  hand 
picks  off  pieces  of  lime,  which  she  masticates  and  swallows  ;  or  she  notices  little 
pieces  of  dirt  on  the  floor  and  takes  them  up  and  puts  them  in  her  mouth.  She  is 
now  offered  a  piece  of  chalk.  She  immediately  grasps  it  and,  without  any  examina- 
tion, puts  it  in  her  mouth,  masticates  and  swallows  it,  although  not  quite  in  the 
same  way  as  she  does  with  a  piece  of  sugar.  It  seems  as  though  she  does  not  fail 
altogether  to  distinguish  sugar  from  chalk,  because  she  masticates  the  chalk  for 
a  long  period,  and  sometimes  looks  as  if  uncertain  to  continue  masticating  or  not ; 
but  she  seems  unable  to  resist  the  temptation  of  the  image  of  sugar  which  the  chalk, 
by  its  similarity,  has  reawakened,  and  so  she  ends  by  swallowing  the  chalk  and 
afterwards  picks  up  any  little  fragments  that  perchance  have  fallen  from  her 
mouth.  There  is,  as  one  can  argue,  a  defect  in  the  perceptions.  These  seem 
elementary  and  not  completed  with  the  help  of  all  the  other  factors  (association) 
which  ought  to  intervene  so  that  a  more  complete  judgment  may  be  arrived  at. 

She  puts  the  chalk  in  her  mouth  apparently  because  it  is  of  the  same  shape  and 
colour  as  a  piece  of  sugar,  these  factors  determining  that  combination  of  move- 
ments which  she  is  accustomed  to  perform  when  she  sees  a  piece  of  sugar  in  front 
of  her.  Possibly  there  is  also  a  defect  of  inhibition,  because  though  she  does  not 
find  it  to  be  sweet,  yet  she  does  not  decide  to  reject  the  chalk  from  her  mouth. 

Her  psychic  life  evidently  manifests  itself  through  the  lower  arcs. 

Reflex  excitability  is  increased  ;  any  noise  makes  her  shake.  She  is  less  courage- 
ous and  does  not  show  to  the  same  extent  that  attitude  of  confidence  and  certainty 
of  which  she  formerly  gave  proof. 

If  one  makes  a  pretence  of  assaulting  her,  she  runs  off,  sometimes  voiding  urine 
in  her  fear,  or  she  hides  herself  in  a  corner  of  the  room  and  cries  out  in  despair. 
She  shows  no  resource  in  defence.  Sometimes  she  does  not  make  off,  nor  seek 
to  hide,  making  no  attempt  either  at  offensive  or  defensive.  What  is  more  remark- 
able is  the  fact  that  when  these  tests  are  repeated  several  times  after  brief  intervals 
she  appears  not  to  remember  that  the  aggression  was  pretended,  and  always  behaves 
in  the  same  way.  Formerly  she  used  to  clasp  and  cling  to  the  leg  of  her  attendant 
in  token  of  affection,  and  pawed  him,  and  rested  her  head  on  him  with  almost 
human  confidence  and  disregard,  like  a  lover  in  sweet  abandonment.  This  no 


164  THE  MECHANISM  OF  THE  BRAIN 

longer  happens.  Men  and  things  are  alike  indifferent  to  her.  She  no  longer  pays 
any  attention  to  the  objects  about  her,  or  else  she  stops  at  everything,  though  only 
for  a  second.  Everything  awakens  her  senses,  but  her  perceptions  are  incomplete, 
erroneous  and  fleeting.  She  no  longer  formulates  complex  judgments,  nor  does 
she  make  use  of  past  experiences. 

EXPERIMENT  9.—  27th  May  1907.— Monkey  A.— A  Cebus,  female,  medium  size.1 

When  she  is  taken  from  the  cage  which  forms  her  particular  section  of  the 
monkey-house,  all  the  other  monkeys  come  forward  to  the  front  of  their  cages, 
shaking  the  iron  railings  and  calling  out  as  though  in  protest. 

The  monkey  A  is  nervous  and  restless.  She  wishes  to  return  to  her  den,  and 
it  is  with  no  small  difficulty  that  we  manage  to  take  her  to  a  room  in  the  laboratory. 
She  attempts  to  clamber  up  every  possible  object  on  the  way,  and  seeks  to  escape, 
heedless  of  calls. 

She  is  entirely  taken  up  with  the  voices  of  her  companions,  and  looks  back  with 
great  anxiety  towards  the  place  where  they  are.  As  we  are  going  through  a  gateway 
some  distance  away,  she  clambers  up  to  the  very  top  of  the  iron  gate  and  spies  out 
the  abode  of  her  companions,  with  whom  she  seems  to  try  to  communicate  by  means 
of  special  cries. 

In  the  laboratory  she  seems  somewhat  irritated.  On  giving  her  a  piece  of  sugar 
wrapped  in  red  paper  she  takes  the  packet,  smells  it  for  a  second  in  a  nervous 
manner,  then  throws  it  away  and  pays  no  more  heed  to  it.  Sometimes  she  grasps 
the  whip  in  my  hand  and  bites  it  nervously. 

She  is  now  given  a  piece  of  sugar.     She  does  not  eat  it  but  throws  it  away. 

She  is  offered  a  pod  of  beans.  She  takes  it  quickly,  opens  it,  takes  the  beans  out 
one  by  one,  puts  them  in  her  mouth,  and  eats  them. 

I  put  a  small  piece  of  white  chalk  in  the  empty  pod  and  present  it  to  her.  She 
opens  it,  is  surprised  at  the  white  content,  takes  it  out,  smells  it,  puts  it  in  her 
mouth  with  diffidence,  and  immediately  afterwards  rolls  it  eight  or  ten  times  between 
her  fingers  as  though,  impatient  and  irritated,  she  wishes  to  destroy  something 
which  has  cheated  her  desire.  Afterwards  she  throws  it  away  and  pays  no  more 
heed  to  it. 

I  now  offer  her  a  small  radish,  which  other  monkeys  eat  very  readily.  She 
takes  it  unwillingly,  and,  after  keeping  it  under  her  eyes  for  a  short  time, 
throws  it  away.  She  seems  to  be  greatly  disturbed  because  taken  away  from  her 
companions. 

30th  May  1907. — As  soon  as  she  is  removed  from  her  cell,  all  the  other  monkeys 
become  excited.  She  goes  with  great  reluctance  to  the  experiment-room,  the  others 
meanwhile  coming  forward  to  the  front  of  their  cages  and  making  a  din. 

I  offer  her  two  cherries,  one  after  the  other,  and  she  eats  them  with  relish.  I 
next  take  the  stalk  of  a  cherry  and  wrap  red  paper  round  one  end,  making  it  as 
nearly  as  possible  of  the  same  size  and  appearance  as  the  real  article.  I  offer  it  to 
her.  She  looks  at  this  imitation  cherry  with  indifference  and  does  not  even  put  out 
her  hand  to  take  it.  Evidently  she  notices  the  unevenness  of  the  surface,  which  is 
not  that  of  a  cherry  (rapid  perception).  At  length,  after  it  has  been  kept  dangling 
under  her  eyes  for  some  time  she  takes  it,  undoes  the  paper  wrappings,  tears  them 
and  throws  all  away.  I  next  offer  her  another  real  cherry.  She  looks  at  it  greedily 
and  darts  forward  to  take  it. 

I  give  her  a  bean.  She  takes  off  the  outer  skin  and  eats  it.  I  drop  a  little 
solution  of  quinine  into  a  bean  pod.  She  commences  to  take  out  the  beans,  notices 
the  bitter  taste,  takes  the  beans  one  by  one,  skins  them  cautiously  with  her  fingers, 

1  A  small  tribe  of  eleven  monkeys  of  the  genus  Cebus,  middle  grade,  was  sent  to 
the  author  in  1906  by  the  Governor  of  Italian  Abyssinia.  They  were  lodged  in 
separate  cages  on  a  terrace  in  the  Institute  at  Naples. 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS    165 

although  in  the  habit  of  shelling  them  with  her  teeth,  and  munches  the  beans 
wherever  the  quinine  has  not  penetrated. 

I  offer  her  a  cherry  dipped  in  solution  of  quinine,  then  dried  and  wrapped  in 
blue  paper.  She  sees  me  wrapping  it  up,  so  that,  after  brief  hesitation,  she  takes  it, 
unwraps  the  paper,  puts  the  cherry  in  her  mouth,  then,  finding  it  bitter,  squashes  it 
between  her  fingers  and  on  the  floor  with  evident  impatience  and  anger. 

I  give  her  another  dipped  in  quinine.  She  eats  the  pulp  very  cautiously,  leaving 
the  skin. 

9th  June  1907. — I  offer  her  a  cherry  wrapped  in  blue  paper.  She  does  not  take 
it,  but  turns  her  head  and  eyes  to  the  other  side.  She  quite  refuses  to  take  it 
(evidently  she  remembers  the  trick  played  upon  her  nine  days  previously  with 
the  cherry  wrapped  in  blue  paper). 

I2th  June  1907. — She  refuses  to  go  to  the  experiment-room,  being  evidently  un- 
willing to  detach  herself  from  her  companions.  With  the  chain  fixed  round  her 
sides  she  is  brought  along,  but  is  always  turning  and  looking  back  towards  the 
terrace  where  the  other  monkeys  are.  As  the  chain  does  not  allow  her  free  move- 
ments she  tries  with  her  hands  and  teeth  to  liberate  herself,  and,  annoyed  at  her 
failure,  finally  gives  it  an  impatient  tug. 

Flies  annoy  her,  and  whenever  one  rests  on  her  head  she  tries  to  get  hold  of  it 
and  chases  it.  I  set  her  at  liberty  in  the  experiment-room.  I  put  some  fruit  on  my 
desk,  at  a  certain  distance  from  where  she  is.  She  looks  at  it,  measures  the  distance 
with  her  eyes,  but  makes  no  attempt  to  lay  hands  on  it,  being  uncertain  whether 
she  can  reach  it  with  one  jump. 

Noticing  me  busy  writing,  she  has  gradually  come  a  little  nearer.  She  takes  up 
her  pole  and,  as  I  make  no  attempt  to  correct  her,  seems  reassured,  clambers  up 
cautiously  and  spies  the  cherries  on  my  desk.  Seeing  I  have  made  no  attempt  to 
chase  her  off,  she  jumps  on  to  the  desk  with  great  precaution  and  takes  some  cherries. 
Having  succeeded  in  this  attempt  she  repeats  it ;  gradually  gaining  in  confidence 
but  watching  me  all  the  time,  she  returns  several  times  until  she  has  taken  them  all. 

She  appears  to  have  no  musical  sense,  or,  at  most,  a  very  rudimentary  one.  She 
shows  fear  at  the  sound  of  the  bugle.  She  gets  excited  and  shows  her  teeth.  She 
has  also  a  great  dislike  for  the  sound  of  a  small  stringed  instrument.  She  is,  how- 
ever, indifferent,  indeed  seems  rather  animated,  when  she  hears  the  sound  of  a  sweet 
wind-instrument. 

19^  June  1907. — She  is  now  quite  at  home  with  me.  She  goes  without  any 
difficulty  to  the  experiment-room.  She  spies  on  to  the  table  where  fruit  lay  on 
former  occasions,  and  clambers  up  to  see  if  there  is  any  there  ;  then  she  comes  up  to 
me,  and  looks  at  me,  as  though  she  wanted  something.  She  searches  my  hands  to 
see  if  there  is  any  fruit  there. 

She  is  irritated  by  the  strident  tones  of  the  bugle.  She  is  indifferent  or  comes 
nearer  if  wind  instruments  are  played  upon.  Some  fruit  is  now  brought  in  and 
placed  on  the  table.  I  give  her  some,  which  she  eats  with  great  delight.  After- 
wards, she  jumps  up  on  the  table,  grasps  the  whip  with  one  hand,  and,  with  a  rapid 
and  very  stealthy  movement  of  the  other,  makes  a  dive  at  the  cherries,  seizing  as 
many  as  she  can.  I  run  after  her  to  take  them  from  her.  She  puts  as  many  as  ehe 
can  into  her  mouth  and  eats  them  greedily  (evidently  she  goes  through  a  somewhat 
long  reasoning  process,  in  so  far  as  she  safeguards  herself  by  getting  hold  of  the  whip 
before  darting  at  the  fruit). 

A  male  monkey  (which  we  will  call  B),  is  now  brought  into  the  room  for  the  first 
time.  He  is  excited,  tries  to  escape  from  his  chain,  and  makes  a  great  din.  He 
quietens  down  shortly  afterwards  as  monkey  A,  now  reassured,  comes  up  to  him. 
They  exchange  vocal  sounds  with  one  another,  sotto  voce.  "Next  they  caress  one 
another.  The  female  begins  to  look  for  insects  all  over  the  body  of  her  male  com- 
panion. B  seems  to  enter  into  a  state  of  ecstasy  and  abandons  himself  to  the 
attentions  of  the  female.  Erection  ensues,  but  he  makes  no  attempt  at  copulation. 


166  THE  MECHANISM  OF  THE  BRAIN 

After  a  time,  as  the  excitement  continues,  he  attempts  to  copulate,  heedless  of  my 
presence.  He  is  prevented  by  the  chain,  and  gives  up  the  attempt.  The  female 
never  touches  the  genital  organs  of  the  male  although  her  cleansing  attentions  are 
directed  mostly  to  the  thighs  and  buttocks.  The  male  afterwards  repeats  the 
insect-hunting  operation  on  the  female,  accompanying  it  with  vocal  murmurings 
and  cadences  that  remind  one  of  the  caresses  bestowed  upon  an  infant.  All  the 
while,  the  female  remains  in  a  state  of  ecstasy,  closing  her  eyes  and  raising  her  hands 
to  allow  him  to  search  the  mammse.  She  abandons  herself  completely  to  his 
attentions  as  he  prosecutes  his  search  in  the  inter-femoral  regions. 

If,  during  these  episodes,  I  throw  down  a  cherry,  there  is  no  show  of  generosity 
on  one  side  or  the  other.  Whichever  can  grab  it  swallows  it,  heedless  of  the  other. 
There  has  been  no  sign,  however,  of  vindictiveness,  or  anger,  or  tendency  to  reaction 
on  the  part  of  either.  Whichever  remains  with  empty  hands  soon  begins  a  friendly 
search  for  insects  on  the  more  fortunate  or  clever  neighbour.  I  leave  the  room  for  a 
moment  and  on  returning  find  them  in  close  embrace,  nose  to  nose,  and  breast  to 
breast.  Whether  or  not  copulation  took  place  I  do  not  know,  but  they  immediately 
separated  and  recommenced  the  insect-hunting  operation.  One  might  almost 
suspect  a  rudimentary  sense  of  shame. 

29th  June  1907. — She  is  even  more  domesticated  and  readily  comes  near.  I 
wrap  some  cherries  in  red  and  some  in  blue  paper.  Those  in  red  paper  are  normal, 
those  in  blue  paper  have  been  passed  through  a  solution  of  bisulphate  of  quinine  or 
injected  with  a  little  of  that  solution.  I  give  her  first  those  in  red  paper  and  she  eats 
them  with  relish.  Next  I  give  her  those  wrapped  in  blue  paper.  Immediately  the 
cherry  touches  her  lips  or  tongue  she  takes  it  from  her  mouth,  opens  it,  nibbles  a 
little  here  and  there,  takes  out  the  stone,  breaks  it,  eats  the  kernel,  and  throws  the 
rest  away. 

The  experiment  is  repeated  a  second  and  a  third  time.  On  the  third  occasion 
the  monkey  does  not  taste  the  cherry  wrapped  in  blue  paper.  She  merely  unwraps 
it,  opens  it,  takes  out  the  stone  to  get  the  kernel,  and  throws  away  the  pulp  (dis- 
tinction of  colours  and  judgment  based  on  memory). 

The  experiment  is  now  repeated  with  Japanese  medlars.  In  the  case  of  those 
wrapped  in  blue  paper,  she  neglects  the  pulp  and  takes  only  the  kernel.  Those 
wrapped  in  red  paper  she  eats  in  the  usual  way. 

From  these  experiments  one  can  infer  : — (1)  That  the  monkey  distinguishes  red 
from  blue  ;  (2)  that  she  is  able  to  associate  the  bitter  taste  of  the  fruit  with  the 
blue  colour  of  the  paper  wrapper;  (3)  that  she  is  capable  of  remembering  the 
association  formed  between  the  colour  and  the  taste,  and  of  formulating  the  judg- 
ment (imagination)  that  the  kernel  is  not  affected  by  the  bitterness,  and  that 
consequently  she  can,  without  risk,  eat  the  kernel,  which  indeed  she  at  once 
breaks,  shells  and  eats  without  any  hesitation. 

A  male  monkey  is  now  brought  in.  They  exchange  compliments.  The  female 
begins  to  look  for  insects  on  the  male.  The  latter  is  in  a  state  of  erection,  but  makes 
no  attempt  at  copulation,  the  presence  of  four  persons  apparently  having  a  re- 
straining influence  (shame  ?)  although  there  has  been  a  considerable  exchange  of 
caresses,  especially  on  the  part  of  the  female.  The  scene  on  separation  after  half-an- 
hour  is  distinctly  painful.  The  male  clings  tightly  to  the  female,  and  howls  desper- 
ately when  forcibly  removed.  The  female,  rather  more  indifferent,  looks  longingly 
after  him. 

I  set  a  looking-glass  before  monkey  A.  She  is  greatly  surprised.  She  follows  all 
the  movements  of  her  image  with  great  curiosity.  She  approaches  the  glass 
cautiously  and  soon  afterwards  tries  to  waylay  the  image  behind  the  looking-glass, 
peeping  round  now  to  the  right,  now  to  the  left.  She  exhibits  a  great  power  of 
observation. 

At  other  two  sittings  on  10th  and  15th  July  similar  results  were  obtained.  On 
the  second  experiment  with  the  looking-glass,  she  seems  persuaded  that  no  other 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS    167 

monkey  is  present  and  is  no  longer  surprised,  nor  has  she  again  looked  for  the  other 
monkey  behind  the  glass. 

25th  July  1907. — She  is  prepared  and  fixed  on  the  operation-table.  Is  very 
agitated.  An  injection  of  chloral  and  morphine  (3  mg.)  is  given.  After  a 
few  minutes,  profound  narcosis.  Whilst  the  hair  is  being  shaved,  respiration 
becomes  feeble  and  then  suspended.  Artificial  respiration.  She  revives  but 
respiration  is  still  superficial,  and  narcosis  remains  profound.  The  animal  is  pre- 
pared with  all  aseptic  precautions.  With  the  trephine  I  make  two  openings,  about 
2  cm.  in  diameter,  in  the  frontal  region,  one  on  each  side,  8  mm.  above  the  orbital 
ridge  and  3  mm.  external  to  the  median  line.  Slight  haemorrhage  from  the  diploe. 
I  cut  around  the  dura  mater  and  reflect  it  to  one  side.  Electric  excitation,  repeated 
here  and  there  all  over  the  anterior  part  of  the  exposed  area,  gives  no  results.  Only 
prolonged  and  fairly  strong  excitation  of  the  upper  and  posterior  part  of  the  exposed 
area  (the  base  of  the  superior  frontal  convolution)  produces  movements  of  the  head 
and  eyes  to  the  opposite  side.  On  exciting  the  interhemispheric  aspect  of  the 
margins  of  the  pre-frontal  sulcus  there  is  produced  a  slight  dilatation  of  the  opposite 
pupil.  Even  on  increasing  the  strength  of  the  current  and  displacing  the  small 
bipolar  electrodes  upwards  and  backwards,  one  succeeds  only  in  provoking  a  slight 
movement  of  the  lower  limb  of  the  opposite  side.  Similar  results  are  obtained  on 
exciting  corresponding  points  on  opposite  sides  of  the  brain. 

I  incise  each  frontal  lobe  at  a  point  corresponding  to  the  pre-frontal  sulcus.  On 
one  side  I  scoop  out  the  cortex  and  remove  over  3  gm.  of  brain  tissue.  On  the 
other  side  I  incise  the  cortex  with  a  bistoury  after  the  manner  of  Shepherd,  mak- 
ing a  vertical  section,  the  knife  penetrating  in  depth  to  the  white  substance,  but 
taking  care  not  to  go  so  deeply  as  to  reach  the  base.  Very  slight  haemorrhage. 
Hsemostasis.  Lavage. 

The  dura  mater  being  stretched  and  its  edges  sutured,  I  stitch  the  overlying  soft 
parts  with  silk  thread,  fixing  the  free  margins  of  the  muscles  to  the  pericranium. 
The  cutaneous  wound  being  closed,  it  is  painted  with  collodion.  Narcosis  lasts 
until  the  following  night.  On  the  morning  of  the  27th  the  monkey  is  quite  con- 
scious. She  takes  a  little  milk.  She  is  pare  tic  in  the  left  lower  limb,  and  walks  on 
the  dorsum  of  the  foot.  It  is  evident  that  she  does  not  recognise  persons  or  things. 

In  order  to  avoid  confusing  the  deficit  produced  by  the  operation  and  the  nar- 
cosis with  that  due  to  the  removal  of  the  frontal  lobes,  I  postpone  methodical 
examination  until  another  day. 

1st  August  1907. — When  the  cage  is  opened  she  remains  indifferent,  and  makes 
no  attempt  to  come  out.  On  removing  her  from  the  cage  she  makes  some  circus 
movements,  four  or  five  times,  from  right  to  left.  On  offering  her  a  plum  she  looks 
at  it  for  a  long  time  before  recognising  it,  and  then  comes  forward  to  take  it.  Move- 
ments of  prehension,  however,  are  badly  directed,  and  she  does  not  reach  the  object 
with  precision.  Finally  she  takes  the  plum,  eats  it,  then  breaks  the  stone,  eats  the 
kernel,  and  afterwards  nibbles  also  the  hard  pericarp.  She  has  no  initiative  : 
remains  beside  her  cage  ;  makes  no  attempt  to  escape,  and  no  longer  responds 
to  the  voices  of  her  companions,  towards  whom  she  appears  to  be  absolutely 
indifferent. 

She  comes  to  the  front  of  the  cage  and  stands  there  for  a  long  time,  rubbing  her 
nose  and  licking  one  of  the  iron  bars  in  a  very  mechanical  and  automatic  fashion.  I 
dangle  a  pear  before  her  eyes  at  a  distance  of  one  metre  or  more.  For  a  long  time 
she  seems  not  to  notice  it.  I  throw  it  on  the  ground,  however,  and  after  some  time 
she  feels  it,  recognises  it  by  the  touch,  takes  it  with  satisfaction  and  eats  it  with 
avidity.  I  suspend  a  slice  of  pear  by  a  thread  and  let  it  swing  like  a  pendulum  in 
front  of  her,  within  the  visual  field.  It  is  only  when  the  pear  reaches  the  middle 
line  of  vision  that  she  notices  it.  Although  she  sees  it  and  turns  her  gaze  on  it, 
recognition  only  takes  place  when,  after  seeing  the  pear  for  some  time,  she  at  length 
puts  her  hand  on  it  with  some  hesitancy,  or  when  it  is  brought  so  near  her  nose  that 


168  THE  MECHANISM  OF  THE  BRAIN 

she  can  smell  it.  She  never  fails  to  notice  contacts  on  the  head  or  trunk,  on  either 
side. 

I  now  set  her  at  liberty.  She  leaves  the  cage  and  comes  into  the  porchway 
walking  well,  except  for  some  paresis  of  the  left  lower  limb.  An  abscess  has  formed 
on  the  left  buttock.  Whether  this  is  due  to  the  cerebral  lesion  (decubitus)  or  to 
the  injection  of  a  syringeful  of  ether  on  the  day  of  the  operation  is  uncertain.  She 
walks,  however,  as  though  she  had  no  idea  of  direction,  and  sometimes  knocks 
against  large  obstacles,  as,  e.gr.,  a  large  flower  vase.  She  keeps  her  head  erect,  as 
under  normal  conditions,  and  moves  it  in  all  directions.  The  dorsum  presents  a 
slight  inward  curvature.  She  has  great  difficulty  in  raising  herself  on  the  lower 
limbs,  in  standing  erect,  and  in  walking  like  a  biped  as  she  did  before  the  operation. 

Hearing  is  well  preserved.  Indeed,  on  taking  her  by  the  neck  to  lead  her  back 
to  her  cage,  she  has  emitted  a  cry  which  has  evoked  calls  from  her  companions,  which 
are  at  some  distance  off,  and  she  has  immediately  replied  with  vocal  utterances, 
in  the  usual  monkey  fashion.  The  tuning-fork  test,  with  the  eyes  closed,  gives 
proof  of  the  integrity  of  hearing  on  both  sides. 

6th  August  1907. — Examination  of  sight.  One  eye  being  covered  in  the  usual 
way,  the  other  eye  is  tested.  In  this  way  it  is  found  that  the  visual  function 
has  been  completely  restored,  the  visual  field  being  normal  for  each  eye  (recogni- 
tion of  objects  and  persons  in  all  sectors  of  the  visual  field).  I  take  four  pieces 
of  a  pear  and  wrap  them  in  red  paper.  I  take  four  similar  pieces,  dip  them  in  a 
solution  of  quinine,  and  wrap  them  in  blue  paper.  I  throw  a  piece  wrapped  in  red 
paper  to  her.  She  unwraps  the  paper  and  eats  the  contents.  I  now  throw  her  a 
piece  wrapped  in  blue  paper.  She  throws  it  away.  A  little  later  I  throw  down 
before  her  a  piece  wrapped  in  red  paper  and  a  piece  wrapped  in  blue  paper.  She 
takes  the  red  but  does  not  even  attempt  to  unroll  the  blue  packet  (she  evidently 
remembers  the  bitter  taste  of  the  previous  experiments). 

She  has  adapted  herself  to  her  surroundings  in  the  cage.  Even  when  it  is 
opened  she  makes  no  attempt  to  come  out  She  exhibits  great  fear  and  has  become 
timid.  If  one  brings  a  cane  near  her,  she  crouches  and  creeps  off  to  a  corner  of  the 
cage.  She  has  an  excessive  fear  of  the  humming  noise  of  the  vibrating  tuning-fork, 
which  she  hears  perfectly  on  both  sides.  Her  eyes  are  now  covered  with  sub-palpebral 
eye-shades  of  caoutchouc.  After  a  short  period  of  restlessness  she  remains  quite 
still.  Under  these  conditions  slight  contacts  on  the  ears,  nose,  back,  chest  and 
hands  are  noticed  equally  well  on  both  sides.  The  wound  is  perfectly  healed. 

15th  August  1907.—  Identical  conditions.  No  change.  She  always  shows  very 
little  enterprise  ;  rather  is  she  full  of  fear.  She  remembers  fairly  well  all  she  had 
learned.  After  being  kept  without  food  for  a  considerable  period  she  succeeds  in 
finding  a  mode  of  opening  a  box  containing  a  pear.  Altogether  she  is  more  timid, 
less  agile,  less  enterprising,  but  still  fairly  intelligent. 

19th  August  1907.— Killed  with  chloroform.  The  brain  is  removed  after  detach- 
ing the  dura  mater  which  is  adherent  to  the  cortex  and  quite  one  with  the  cicatrix 
on  the  left  side.  The  left  hemisphere  has  been  deprived  of  a  part  of  the  pre-frontal 
lobe  by  a  section  which  has  fallen  2  mm.  in  front  of  the  pre-frontal  sulcus.  The 
superior  and  internal  part  of  the  frontal  lobe  has  been  spared,  so  that  from  the 
margin  of  the  section  there  is  a  distance  of  about  one  centimetre  and  a  half  to  the 
interhemispheric  margin.  The  pole  of  the  frontal  lobe  is  spared,  and  is  continuous 
below  with  the  orbital  surface  and  externally  with  the  opercular  part  of  the  first 
Bolandic  convolution. 

The  right  hemisphere  is  almost  intact.  The  incision  is  limited  to  the  middle 
area.  The  first  frontal  convolution,  which  is  uninjured,  and  the  inferior  part  of 
the  frontal  lobe,  are  continuous  with  the  rest  of  the  brain.  The  incision  has  fallen 
£  cm.  in  front  of  the  pre-frontal  sulcus.  The  brain  is  immersed  in  Muller's  fluid, 
for  subsequent  examination  by  Marchi's  method. 

This  case  serves  as  a  good  control,  inasmuch  as  it  shows  that  partial  lesions, 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     169 

oven  although  they  affect  both  frontal  lobes,  do  not  produce  the  great  frontal 
syndrome.  The  symptomatology  is  reduced  to  a  change  of  character  which  is 
represented  at  most  by  indifference,  inactivity,  fear,  and  lack  of  interest,  curiosity, 
initiative  and  reactivity. 

EXPERIMENT  10. — 4th  September  1907. — Monkey  B. — Male,  slightly  larger  than 
Monkey  A,  lively,  intelligent,  daring,  artful,  very  agile  and  circumspect.  He  goes 
around  the  room,  jumps  on  chairs  and  other  articles  of  furniture,  takes  various 
objects  in  his  hands,  examines  them,  lays  them  down,  sometimes  carries  them  off, 
so  that  it  is  necessary  to  run  after  him  in  order  to  get  them.  He  takes  papers, 
unfolds  them,  refolds  them,  crumples  them  up  and  tears  them.  He  dips  his  index 
finger  into  the  ink-bottle,  then  looks  at  it  surprised,  gazes  at  me  and  does  not  know 
what  to  do  with  the  finger,  wet  and  black  at  the  tip,  but  finally  decides  to  clean  it 
by  rubbing  it  on  the  hair  of  his  body. 

He  jumps  up  on  the  window-ledge  and  calls  to  his  companions,  who  respond  in 
turn.  During  four  days  he  has  learned  to  recognise,  with  equal  facility,  red  and 
blue  packets,  the  former  containing  pieces  of  pear  or  small  plums  in  good  eating 
condition,  whilst  the  latter  contain  the  same  fruit,  but  made  bitter.  On  the  fourth 
day,  those  wrapped  in  blue  paper  had  not  even  a  glance  bestowed  upon  them,  even 
when  the  monkey  had  been  rendered  hungry  by  long  fasting. 

When  left  alone  in  the  laboratory  and  observed  through  a  small  spying  aperture, 
he  makes  a  tour  of  inspection  all  around,  jumps  on  chairs  and  tables,  takes  up 
objects,  examines  them,  lays  them  down,  takes  up  some  waste  papers  left  there 
on  purpose  and  tears  them,  apparently  finding  pleasure  in  the  tearing  sound,  as 
happens  with  infants  of  three  or  four  years.  He  makes  several  attempts  to  open 
the  well-closed  drawer  from  which  the  fruit  given  to  him  was  generally  taken. 
He  fails  in  the  attempt,  jumps  up  on  the  ledge  of  the  window  and  calls  to  his 
companions. 

10th  September  1907. — He  has  been  kept  apart  in  a  large  cage  for  several  days 
and  I  now  put  a  female  monkey  C  into  the  cage  beside  him.  The  meeting  is  very 
cordial  and  effusive.  They  embrace  and  hug  one  another.  The  female  more 
particularly  seems  to  feel  the  need  of  protection  and  remains  clinging  to  the  male, 
grasping  him  preferably  from  behind.  Occasionally  they  hug  one  another,  face 
to  face,  and  almost  seem  to  be  kissing.  They  search  one  another  for  insects  and 
seem  to  enjoy  the  operation  immensely,  for  they  assume  attitudes  of  ecstasy. 

The  male  exercises  the  right  over  prey  (food).  If  I  put  a  pear  at  the  front  of  the 
cage  it  is  always  the  male,  never  the  female,  who  takes  it.  On  one  occasion  the 
female  monkey  has  attempted  to  take  half  a  pear  which  has  fallen  into  the  cage, 
but  the  male  has  prevented  her  with  the  energetic  and  domineering  gesture  of  a 
master.  I  lay  down  two  pears  beside  one  another  at  the  front  of  the  cage.  The 
male  takes  one,  then,  when  the  female  (C)  attempts  to  take  the  other,  he  brusquely 
pushes  her  aside  with  an  incomprehensible  gesture.  To  make  sure  that  he  will 
get  the  second  pear,  he  lays  down  half  of  the  one  that  he  took  first,  puts  his  foot 
over  it,  and  uses  his  free  hands  to  get  hold  of  the  other,  which  does  not  readily 
pass  through  the  space  between  the  iron  bars  of  the  cage.  The  female  then  brings 
her  nose  near  to  that  of  the  male,  who  meanwhile  eats  greedily  away  without  giving 
any  share  to  the  female.  The  latter,  in  full  subjection  to  her  male  companion,  has 
to  play  the  rftle  of  spectator,  and  content  herself  by  gathering  up  any  morsels  that 
may  drop.  During  the  whole  day  there  has  not  been  a  single  action  of  generosity 
on  the  part  of  the  male.  Even  when  the  female  takes  up  any  morsel  that  he  has 
let  fall,  she  does  so  timidly,  as  though  awaiting  her  companion's  consent.  Three 
or  four  times  in  the  course  of  an  hour  the  male  has  made  attempts  at  copulation, 
sometimes  apparently  on  the  invitation  of  the  female,  who  has  held  up  her  tail 
and  exposed  her  genitals.  The  sexual  act  is  preceded  by  lengthy  tactile  preparations 
but  is  not  completed,  because  the  female  twice  makes  her  escape. 


170  THE  MECHANISM  OF  THE  BRAIN 

18th  September  1907. — To-day  he  is  again  brought  into  the  experiment-room. 
He  comes  without  any  reluctance,  possibly  because  he  has  a  pleasant  recollection 
of  the  previous  experiment.  Experience  has  now  taught  him  to  recognise  sugar 
and  distinguish  it  from  chalk.  I  take  a  piece  of  each  from  the  drawer  in  my  desk 
and  show  them  to  him  at  some  little  distance,  the  sugar  in  my  right  and  the  chalk 
in  my  left  hand.  He  greedily  puts  out  his  hand  towards  mine  with  the  sugar  but 
I  quickly  close  my  hand  before  he  can  take  it.  I  put  both  hands  behind  my  back 
and  then  bring  them  forward  again  in  front  of  him.  I  open  them  and  again  he 
casts  a  glance  of  envy  at  the  sugar  in  my  right  hand,  and  a  second  time,  as  he  is 
making  a  rapid  movement  to  take  it,  I  forestall  him  by  closing  my  hand.  I  repeat 
the  experiment  but,  whilst  my  hands  are  at  my  back,  I  change  the  sugar  from  my 
right  to  my  left  hand.  I  now  bring  the  hands  forward,  keeping  them  closed  and 
quite  near  him.  He  seems  to  be  quite  ravenous  and  tries  in  every  way  to  force 
open  my  right  hand,  in  which  he  has  twice  seen  the  sugar.  After  a  time  I  open  the 
hand  and  he  quickly  seizes  the  white  cube  but,  immediately  recognising  it  as  chalk, 
throws  it  away  and  at  once  tries  to  open  the  other  hand,  which  all  the  time  has  been 
kept  closed  before  him.  I  take  a  roasted  chestnut,  of  which  he  is  very  fond,  attach 
a  thread  to  it,  and  move  it  before  him  in  such  a  way  that  I  can  withdraw  it  each 
time  he  puts  out  his  hand  to  take  it.  Indeed,  he  makes  many  efforts  to  grasp  it, 
but  I  remove  it  in  time,  so  that  he  is  disappointed.  Sometimes  the  movement  of 
prehension  is  so  rapid  or  the  apparent  inattention  of  the  monkey  so  well  feigned 
that  I  have  not  been  quick  enough,  and  he  has  managed  to  get  it.  This  has  happened 
when,  after  several  vain  attempts  to  grasp  it,  he  has  pretended  to  pay  no  more 
attention  to  it  and  sometimes  has  turned  his  head  away  with  an  air  of  refusal. 
If,  whilst  in  this  attitude,  I  brought  the  chestnut  rather  near,  then,  with  lightning 
rapidity  and  precision,  he  succeeded  in  snatching  it  before  I  had  time  to  withdraw 
it.  There  was  evidently,  here,  an  attempt  at  dissimulation  with  the  object  of 
deceiving  (memory  and  imagination). 

24th  September  and  ±th  October  1907. — Experiments  repeated  in  similar  fashion. 

16^  October  1907. — Mutilation  of  the  left  frontal  lobe,  following  the  usual 
practice.  Operation  without  noteworthy  incident.  Haemorrhage  readily  con- 
trolled. Cross  section  of  the  dura  mater,  and  reflection  of  the  four  segments  on  the 
edge  of  the  breach.  Electric  excitation  of  the  feet  of  the  frontal  convolutions.  The 
areas  of  excitation  for  the  muscles  of  the  neck,  eyes,  pupils  and  ear  are  defined  in 
the  same  order  as  before,  in  the  neighbourhood  of  the  pre-frontal  sulcus.  I  scoop 
out  the  cortex  of  the  frontal  lobe  (superior  and  inferior  convolutions).  The  weight 
of  cerebral  substance  removed  is  six  grammes  and  a  fraction.  Haemostasis.  Lavage 
of  th  surface  of  the  wound  and  of  the  breach  with  sterilised  water  ;  suture  of  the 
lips  of  the  dura  mater,  and  then  of  the  pericranium  and  overlying  soft  parts  ; 
dressing  with  iodoform  and  collodion.  The  monkey,  already  partly  awake,  is  now 
placed  upon  a  couch.  He  lies  quite  limp. 

I  omit  the  notes  of  the  first  few  days  because  they  are  of  little  use. 

19th  October  1907. — He  walks  well.  One  can  just  detect  a  certain  difference 
in  the  movements  of  the  limbs  of  the  right  side.  He  seems  restless  ;  walks  about 
the  room  like  one  dysorientated  ;  now  he  jumps  up  on  a  window,  now  on  a  chair. 
He  has  a  preference  for  corners,  but  remains  only  a  short  time  in  one  position.  He 
turns  round  his  head  and  eye?-  like  one  in  a  dream.  In  any  case  one  does  not  find 
the  usual  air  of  curiosity  and  craftiness  in  his  attitude  and  look.  His  glance  is  more 
lifeless  ;  he  has  an  air  of  indifference.  He  approaches,  without  any  suspicion, 
people  of  whom  he  was  formerly  afraid.  He  has  been  noticed  several  times  scratch- 
ing his  head  with  the  right  hind  limb  and  taking  pieces  of  apple  with  the  right 
hand,  with  fair  precision  in  his  movements.  No  circus  movement.  At  no  time 
has  he  shown  deviation  of  the  head  towards  one  or  other  side,  no  curvature  of  the 
trunk  or  of  the  neck.  He  seems  to  have  lost  his  reactive  nature,  even  when  one 
takes  away  his  food  from  before  him,  although,  prior  to  the  operation,  he  took 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     171 

possession  of  it  with  an  air  of  authority  and  would  not  leave  it  in  spite  of  threats 
or  violence. 

1st  November  1907. — The  examination  of  the  visual  field  has  shown  vision  to  be 
defective  in  the  external  half  of  the  right  eye,  and  at  the  extreme  right  of  the  left 
visual  field.  It  is  needless  to  repeat  here  the  method  followed  in  measuring  the 
visual  field.  Suffice  it  to  say  that  it  has  given  fairly  precise  and  reliable  results. 

10th  November  1007. — Torpid  and  dysorientated.  Recognises  fruits  but  -does 
not  distinguish  the  deceptions  practised  upon  him  with  the  same  rapidity  and 
precision  as  before.  For  example,  he  was  given  a  sham  pear  made  of  bread  paste 
allowed  to  harden  and  then  painted.  When  the  animal  was  in  good  health  he  recog- 
nised the  deception  after  the  first  trial,  and  subsequently  paid  no  more  attention 
to  it.  Since  his  operation  he  has  persisted  in  taking  it  and  breaking  it  angrily 
with  his  teeth. 

He  is  indolent,  timid,  indifferent,  has  no  initiative,  and  will  remain  for  a  long 
time  in  a  corner  of  the  room. 

He  eats  well,  taking  food  equally  well  with  either  hand  and  carrying  it  to  his 
mouth  with  precise  movements.  If  one  holds  a  small  apple  firmly  in  the  hand  and 
offers  it  to  him,  he  will  take  it  if  allowed  but  will  not  make  persistent  and  forcible 
efforts  to  obtain  it  as  he  did  before  the  operation.  He  is  more  submissive  than  he 
was.  There  seems  to  be  a  slight  weakness  about  the  right  hand. 

22nd  November  1907. — A  second  operation,  on  the  right  side.  No  serious 
incident  during  the  operation.  Faradic  excitation  ;  identical  results,  which  are 
summarised  in  the  chapter  following.  The  incision  was  inclined  from  behind 
forwards,  commencing  about  two  millimetres  in  front  of  the  pre-frontal  sulcus, 
leaving  in  situ  a  part  of  the  cortex  at  the  anterior  pole.  Suture  and  aseptic  dressing 
as  usual. 

23rd  November  1907. — Great- depression  and  prostration.  He  has  never  moved 
from  his  couch  since  the  operation,  nor  has  he  taken  any  food.  He  displays  a 
profound  indifference.  If,  however,  we  catch  him  by  the  back  and  attempt  to 
chase  him  from  his  couch  he  clings  with  his  hands  to  the  iron  bars.  When  put  on 
the  ground  he  curls  himself  up  and  lies  prostrated. 

24th  November  1907. — He  is  able  to  take  some  milk.  His  condition  is  but  little 
altered  although  there  are  appreciable  signs  of  commencing  improvement.  He  is 
able  to  raise  his  head,  to  look  around,  to  rise  up  and  stand  on  his  legs  for  a  few 
moments. 

29th  November  1907. — During  the  past  three  days  he  appears  to  have  recovered 
from  the  first  post-operative  phase,  which  has  been  fairly  severe.  His  condition 
is  now  such  that  methodical  examination  can  be  undertaken. 

He  is  torpid  and  indifferent  to  all  that  occurs  around  him.  He  remains  curled 
up  in  a  corner  of  the  room  for  a  long  time  without  moving,  sometimes  with  the 
head  bent.  He  passes  to  another  corner  of  the  room,  apparently  without  any 
object,  rather  from  a  pure  automatic  impulse,  and  assumes  the  same  attitude. 
Sometimes  he  jumps  up  on  the  window  but  does  not  call  out.  He  eats  when  food 
is  proffered  him — a  piece  of  bread,  a  chestnut,  an  apple  ;  but  he  does  not  peel 
the  chestnut  with  the  same  smartness,  nicety  and  care  that  he  exhibited  under 
normal  conditions,  and  sometimes  he  even  eats  the  skin.  In  any  case  he  is  rather 
filthy, 

C>th  December  1907. — Remains  in  the  same  condition.  He  is  full  of  fear.  A 
slight  noise  is  sufficient  to  make  him  suddenly  jump  and  show  signs  of  terror.  Ex- 
amination of  tactile  sensibility  in  all  points  of  the  body  is  quite  negative.  Attempts 
to  prick  him  or  pull  hairs  from  his  back  or  head  provoke  emotions  of  fear,  with 
tremblings,  cries  and  efforts  to  escape. 

Sight,  measured  in  the  usual  way,  is  normal  on  the  right  side,  though  less  clear 
towards  the  inner  angle.  On  the  left  side,  proceeding  from  within  outwards,  clear 
vision  ends  at  a  point  corresponding  to  a  vertical  line  passing  through  the  visual 


172  THE  MECHANISM  OF  THE  BRAIN 

axis.     Repeating   the   experiment  from  without  inwards,   he   sees   the   object   (a 
roasted  chestnut,  peeled)  clearly,  even  before  it  reaches  that  line. 

10th  December  1907.  — Condition  as  already  described.  The  following  experiment 
is  made.  Being  rendered  hungry  by  prolonged  fasting,  he  is  allowed  to  see  a  dish 
containing  pieces  of  apples  and  roasted  chestnuts.  He  is  agitated  at  the  sight  of 
the  food,  and  extends  his  hand  to  take  it,  but  I  withdraw  the  plate  and  place  it  on 
the  top  of  a  bookcase  about  two  metres  high.  The  monkey  begins  to  jump  and 
clamber  up  the  panels  of  the  door  of  the  bookcase.  Half-way  up,  he  slips  on  the 
smooth  surface  and  falls  back  to  the  ground.  He  takes  up  a  position  about  half  a 
metre  in  front  of  the  bookcase,  and  renews  the  attempt  in  the  same  way  with  the 
same  result.  He  repeats  this  attempt  twelve  times  in  the  presence  of  one  of  my 
assistants  and  myself,  without  any  modification  whatsoever,  the  rhythmic  character 
of  the  process  being  indeed  surprising,  and  showing  all  the  characters  of  a 
stereotyped  movement  or  a  tic. 

I  now  bring  into  the  room  the  female  monkey  C.  She  goes  up  to  B,  walks 
around  him,  petting  and  caressing  him,  and  looking  at  him  with  much  curiosity. 
B  makes  but  little  response  to  all  C's  manifestations  of  friendliness.  He  remains 
torpid  and  indifferent,  showing  at  most  some  signs  of  satisfaction  when  C  touches 
him  about  the  neck,  especially  when  she  strokes  and  fondles  him  there.  He  seems 
to  experience  very  little  sexual  excitement,  even  when  solicited  by  the  female.  If 
he  does  make  an  attempt  at  copulation  it  is  futile,  wholly  lacking  in  that  vigour  and 
boldness  that  were  so  marked  in  him,  as,  indeed,  in  all  normal  monkeys,  prior  to 
operation.1 

The  wounds  are  now  completely  closed. 

20th  December  1907. — Conditions  identical.  His  life  is  solitary,  stupid  and 
stereotyped.  He  crouches  in  a  corner  and  only  leaves  that  position  to  pass  to 
another  spot  in  the  room,  with  movements  that  are  rhythmic  and  always  the  same. 
When  along  with  other  monkeys  he  takes  no  share  in  their  caresses  and  merriment. 
He  recognises  his  food  and  eats  regularly,  but  is  more  filthy.  Indeed,  he  makes  a 
dreadful  mess  of  himself  if  not  carefully  attended,  to.  If  given  food  in  a  basin  in 
common  with  the  others,  he  generally  eats  nothing.  When  three  of  them  are  together 
in  a  room,  and  pieces  of  apple  or  chestnuts  are  thrown  on  the  ground,  he  never 
succeeds  in  getting  any,  because  the  other  two  are  much  more  alert.  Were  it  not 
for  the  care  bestowed  upon  him  in  giving  him  food  apart  from  the  others,  he  would 


1  In  order  to  emphasize  the  anomaly  of  this  frigid  and  stupid  behaviour  on  the 
part  of  a  monkey  that  has  suffered  mutilation  of  the  frontal  lobes,  I  cite  here  one  of 
many  control-experiments  that  served  as  a  guide  to  examination. 

Three  monkeys  which  hitherto  have  been  kept  in  separate  cells  are  brought 
together  in  the  laboratory — Alpha,  a  large  female,  Beta,  a  smaller  female,  and  Delta, 
a  male  monkey  larger  than  either  of  the  females.  Hardly  have  they  set  eyes  upon 
one  another  when  Delta  attempts  copulation  with  Alpha.  The  latter  fondles  and 
caresses  the  male  and  embraces  him  amorously.  Soon  afterwards  they  commence 
insect-hunting  operations  on  one  another,  each  submitting  in  turn  to  the  other  in 
a  voluptuous  attitude.  Meanwhile  Beta  remains  a  melancholy  spectator.  I  throw 
a  cooked  potato  on  the  floor.  Beta  runs  to  pick  it  up.  The  other  two  are  too  busy 
to  think  of  eaiing.  They  stand  embracing  one  another ;  they  follow  each  other 
around  ;  they  caress  one  another.  It  is  a  regular  flirtation.  Then  comes  a  moment 
when  Alpha  leaves  her  companion  to  jump  up  on  the  window-ledge  and  call  out  to 
her  friends  in  the  monkey-house.  Beta  seizes  advantage  of  the  opportunity  and 
offers  herself  to  Delta.  Alpha  appears  to  grasp  the  situation,  for  she  immediately 
jumps  down  from  the  window  and  rushes  at  Beta,  driving  her  away  and  pulling  her 
by  the  hair,  whilst  Delta,  the  courted  one,  looks  on  calmly  as  the  two  females  settle 
their  affair,  though  perhaps  not  without  a  benevolent  glance  towards  Beta,  which, 
being  the  smaller  and  weaker,  gets  the  worst  of  the  encounter. 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS    173 

certainly  be  victimised  by  his  companions  who,  on  questions  of  food,  are  not  very 
generous  with  one  another.  In  this  respect  his  behaviour  and  lot  resemble  those  of 
low-grade  human  imbeciles. 

22nd  December  1907. — On  post-mortem  examination  the  two  frontal  lobes  are 
seen  to  be  decorticated  over  a  considerable  area,  from  the  pre-frontal  sulcus  to  the 
pole,  rather  deeply  so  in  the  centre  of  this  area.  On  both  sides  the  parts  spared 
comprise  the  whole  of  the  orbital  surface  along  with  the  external  margin  of  the 
second  frontal  convolution  and  the  entire  interhemispheric  surface  along  with  a 
part  of  the  superior  frontal  convolution. 

EXPERIMENT  11. — 28th  November  1907. — Monkey  C.  Female.  The  same 
which  lived  for  some  time  with  the  male  B. 

Rather  small  but  very  intelligent,  smart,  lively,  observant  and  curious.  She 
is  fond  of  the  company  of  other  monkeys,  so  that  she  is  in  great  despair,  cries  and 
calls  out,  and  is  very  unsettled,  when  taken  from  her  quarters  to  the  observation- 
room.  Although  there  are  many  intervening  objects  between  this  room  and  the 
monkey  quarters,  she  peeps  out  every  time  the  door  is  opened  and  does  her  best  to 
get  out.  She  goes  around  the  room  taking  stock  of  the  few  pieces  of  furniture 
which  are  there.  She  jumps  up  on  the  window-ledge  in  order  to  spy  better  down 
the  garden,  and  gives  a  call.  She  takes  apples  quickly  and  eats  them  with  avidity. 
She  does  not  know  the  chestnut,  for  she  sees  it  for  the  first  time,  and  is  not  aware 
that  it  is  good  food.  I  peel  one  and  offer  it  to  her.  She  examines  it,  tastes  it 
cautiously  at  first,  and  then  eats  it.  She  is  not  afraid  of  the  rod  with  which  she  is 
threatened,  for  in  the  past  there  have  been  several  threats  which  did  not  materialise. 
She  seems  much  less  wild  than  she  was,  and  is  commencing  to  understand  the  com- 
mand "  Give  me  your  hand,"  without  me  making  any  sign  or  putting  out  my  hand. 
I  put  an  apple  on  the  cornice  of  the  bookcase.  She  clambers  up  over  the  door  and 
almost  manages  to  get  it,  making  use  of  every  projection  of  the  wood  as  a  point  of 
support,  precisely  as  a  man  would  do.  After  two  trials,  as  there  are  no  further 
points  of  support,  all  being  smooth,  she  abandons  the  attempt. 

1st  December  1907. — She  is  offered  a  chestnut ;  she  recognises  it  at  once,  takes  it, 
strips  off  the  skin,  and  eats  it  with  great  satisfaction.  I  give  her  a  sham  pear.  She 
shows  even  greater  pleasure  at  the  sight  of  this  but,  having  taken  it,  she  turns  and 
rolls  it  in  her  hands,  brings  it  up  to  her  mouth,  remembering  the  pears  it  resembles, 
for  she  has  often  partaken  of  this  fruit,  but  changes  her  attitude  and  seems  vexed. 
After  having  felt  it  many  times,  scrutinised  it,  smelt  it,  and  tried  it  between  her  lips 
and  teeth  and  on  her  tongue,  she  ends  by  throwing  it  away  and  does  not  look  at  it 
again  except  with  an  air  of  indifference. 

3rd  December  1907. — I  take  her  into  my  private  room  and  leave  her  at  liberty. 
She  makes  a  tour  of  inspection  all  over  the  room  as  though  trying  to  get  her  bearings. 
At  first,  every  time  the  door  is  opened  she  tries  to  make  her  exit.  She  clambers  up 
to  the  ledge  of  the  window,  spying  through  the  window  towards  the  place  where,  at 
some  distance  off,  her  companions  are,  calling  out  repeatedlj'  and  never  remaining 
at  rest.  The  others  reply,  so  she  peers  out  more  anxiously  still,  and  cries  as  though 
she  were  hailing  them. 

I  repeat  the  experiment  with  the  apple  on  the  cornice  of  the  bookcase.  She 
clambers  up  and  succeeds  in  taking  it,  exhibiting  marvellous  precision  in  her  move- 
ments. She  has  jumped  up  on  my  writing-table  but,  as  she  has  knocked  over  some 
papers,  I  rise  up  and,  taking  the  rod  in  my  hand,  assume  a  threatening  attitude. 
She  makes  her  escape  and  hides  under  a  couch.  I  sit  down  to  write  again.  She 
remains  hidden  behind  the  couch  which  is  directly  in  front  of  me,  but  from  time  to 
time  clambers  up  the  back  of  it  and  craftily  protrudes  her  head  to  spy  what  I  am 
doing.  If  my  eyes  encounter  hers  she  immediately  hides  herself.  She  is  very 
partial  to  apples,  so  I  now  put  three  of  these  on  my  writing-table  and,  going  to  an 
arm-chair,  sit  down  to  read.  Again  she  peeps  from  behind  the  couch,  and,  as  soon  as 


174  THE  MECHANISM  OF  THE  BRAIN 

she  feels  safe,  she  cautiously  makes  one  spring  forward  like  a  skilful  thief,  seizes  an 
apple  and  returns  to  her  hiding-place.  I  follow  her  and  threaten  her  with  the  whip, 
and  then  for  a  long  time  she  refrains  from  making  any  further  attempt  (inhibition, 
memory).  She  has  allowed  the  two  apples  to  remain  on  my  writing-table,  although 
still  very  hungry.  Indeed,  when,  after  a  time,  I  call  her  to  rne  and  offer  her  another 
apple,  she  approaches  at  once  without  fear  and  snatches  it  from  my  hand  with 
surprising  precision  and  rapidity. 

I2th  December  1907. — I  have  again  taken  her  to  the  study  where  I  am  alone. 
She  is  much  more  domesticated.  She  has  not  jumped  up  on  the  writing-table, 
although  there  are  apples  there  as  in  the  former  experiment.  Twice  she  has 
cautiously  clambered  up  the  legs  of  the  table  to  spy  my  attitude,  but  it  has  sufficed 
for  me  to  say  "  No  "  to  induce  her  immediately  to  descend  and  refrain  from  any 
further  attempt.  I  now  give  her  a  piece  of  apple  that  has  been  dipped  in  a  solu- 
tion of  quinine,  and  although  she  is  very  hungry,  having  been  kept  without  food,  she 
immediately  notices  the  bitter  taste,  and  seems  surprised  and  vexed.  She  smells  it, 
licks  it  cautiously,  and  then  lays  it  aside.  Several  times  as  she  has  been  touring 
around  the  room  she  has  gone  up  to  the  rejected  apple,  handled  it,  examined  it, 
smelt  it  and  then  left  it  alone.  After  a  long  time,  urged  by  hunger  and  desire,  for 
she  has  had  no  food,  she  has  decided  to  eat  it ;  she  begins  studiously  at  the  centre 
and  proceeds  gradually  towards  the  periphery  until  she  comes  to  the  bitter  part, 
then  discards  the  outer  layer  of  the  piece  of  apple. 

I  have  placed  three  apples  on  the  arm-chair  near  the  table.  She  has  made  three 
attempts  to  approach  the  place,  watching  my  eyes,  but  it  has  been  enough  for  me  to 
say  "  No  "  to  induce  her  to  retreat.  Next,  she  has  taken  a  turn  round  the  room 
examining  everything  in  it,  and  then  she  has  hidden  behind  the  couch  and  several 
times  has  peeped  over  it,  to  see  if  I  were  awake,  or  if  I  were  disposed  to  offer  her  an 
apple.  She  has  made  no  attempt  to  steal  them.  It  is  only  after  the  lapse  of  an 
hour  that  she  has  come  forward  to  me  very  timidly  and  circumspectly,  meeting  my 
gaze  and  then  turning  round  towards  the  apples.  I  now  offer  her  one  and  she  takes 
it  from  my  hand  with  great  joy  and  avidity. 

I  have  given  her  a  piece  of  apple  immersed  in  solution  of  quinine.  She  has  im- 
mediately recognised  it  and  left  it  alone,  evidently  having  a  good  recollection  of  the 
previous  experiment,  for  she  has  spent  no  time  over  the  examination.  I  now  throw 
in  front  of  her  some  small  packets  containing  sugar,  pieces  of  apple,  and  chestnuts, 
wrapped  in  red  paper,  and  other  packets  containing  pieces  of  chalk,  pieces  of  apple 
dipped  in  solution  of  quinine,  and  artificial  chestnuts  composed  of  chalk  and  saw- 
dust, wrapped  in  blue  paper.  She  opens  them  one  after  another  just  as  she  comes 
upon  them,  eating  the  contents  of  the  red  packets  and  throwing  away  the  contents 
of  the  blue  packets  after  a  brief  examination,  paying  no  more  heed  to  them.  After 
a  lapse  of  one  hour  I  repeat  the  experiment.  I  am  not  convinced  that  she  notices  the 
colour  of  the  packets,  because  she  repeats  the  examination  of  their  contents  in  the 
same  way. 

13th  December  1907. — She  has  been  rendered  hungry  by  prolonged  fasting.  I 
now  throw  in  front  of  her  red  and  blue  packets  alternately.  After  two  experiments 
she  commences  to  show  some  doubt  as  to  the  blue  packets.  Nevertheless  she 
unwraps  them  and  throws  a,wa,y  the  contents  with  an  air  of  disdain. 

14th  December  1907. — She  has  not  had  any  food  since  last  night.  When  brought 
to-day  into  the  observation-room,  I  give  her  a  red  packet,  which  she  takes  with  con- 
fidence and  rapidity,  unwraps  it  and  without  any  diffidence  takes  the  content, 
putting  it  at  once  in  her  mouth,  and  eating  it  with  relish.  I  now  offer  her  a  blue 
packet.  She  takes  it  with  some  diffidence,  unwraps  it  without  enthusiasm,  recognises 
the  content,  and  without  delaying  much  over  it  as  in  the  former  experiments, 
throws  it  away,  although  there  is  no  doubt  her  appetite  is  still  unsatisfied. 

1 5th  December  1907. — Operation.  Narcosis.  Bilateral  trepannings,  half  a 
centimetre  above  the  supraciliary  orbital  ridges.  Strict  aseptic  precautions.  No 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  £  MONKEYS    175 

haemorrhage.  Section  and  reflection  of  the  dura  mater  is  made  without  the  occur- 
rence of  any  unpleasant  incident.  Electric  excitation  reveals  a  small  area  in  the 
middle  of  the  pre-frontal  sulcus  (about  half  a  centimetre  in  front  of  the  excitable 
area  for  extension  of  the  hand  and  wrist),  which  gives  rise  to  dilatation  of  the  pupil 
of  the  opposite  side.  On  displacing  the  small  bipolar  electrodes  a  little  higher  on 
the  same  line,  a  combined  movement  of  the  eyes  to  the  opposite  side  and  dilatation 
of  the  pupil  is  obtained.  Passing  still  higher  to  the  foot  of  the  first  frontal  con- 
volution, we  get  co-ordinated  movements  of  rotation  and  inclination  of  the  head 
and  of  the  eyes  to  the  opposite  side.  At  a  point  still  higher  up,  near  the  inter- 
hemispheric  margin,  we  get  movements  of  the  head  to  the  opposite  side,  slight 
movement  of  the  pelvis  with  a  tendency  to  curvature  inwards,  and  an  upward 
movement  of  the  tail.  With  the  help  of  careful  assistants  these  observations  were 
repeated  several  times  with  the  same  results,  the  animal  being  kept  in  a  state  of 
slight  narcosis.  It  is,  however,  to  be  remarked  that  symmetrical  correspondence 
between  the  two  sides  is  not  perfect  either  in  the  case  of  the  area  of  excitation  for 
the  external  ocular  muscles  and  the  iris  or  that  of  the  hand.  At  a  point  very  close 
to  that  of  the  ocular  muscles,  but  underlying  it,  excitation  produces  movements  of 
the  opposite  ear,  and  a  little  further  below  and  behind  is  a  small  area,  excitation  of 
'which  gives  rise  to  slight  blinking  movements  of  the  eyelids,  resembling  those  that 
occur  when  the  eye  is  rather  irritated  by  light.  With  a  cataract  knife  1  incise  the 
cortex  between  the  area  of  the  upper  arm,  and  that  of  the  pupil,  but  much  nearer 
the  latter  point,  making  a  curved  incision  with  convexity  upwards  and  backwards 
so  as  to  spare  the  area  for  conjugate  movements  of  the  head  and  eyes,  and  of  the 
trunk,  on  the  foot  of  the  superior  frontal  convolution.  For  protection  I  insert  a 
small  spatula  and  scoop  out  the  exposed  cortical  area,  proceeding  from  behind 
forwards,  and  removing  what  of  the  cortex  lies  in  front  of  the  incision.  The  lesion 
in  the  left  cortex  is  deeper  than  that  in  the  right.  The  weight  of  cerebral  tissue 
removed  is  five  grammes. 

16th  December  1907. — She  is  depressed  and  immobile.  She  lies  on  the  couch 
with  her  head  and  her  arms  spread  out.  The  upper  limbs  are  cold  and  somewhat 
cedematous.  The  lower  limbs  are  cold  but  dry.  On  being  shaken,  she  opens  her 
eyes  and  raises  her  head.  She  has  been  without  food  for  thirty-six  hours,  and  now 
shows  a  desire  to  have  a  slice  of  apple  when  it  is  placed  near  her.  As,  however,  she 
cannot  take  it  with  her  hands,  she  moves  her  head  and  body  forwards  slowly  and 
without  energy  so  as  to  reach  it  with  her  mouth,  but,  soon  after,  exhausted  by  the 
effort,  lets  it  drop.  She  is  given  a  subcutaneous  injection  of  sulphuric  ether  and  is 
wrapped  in  warm  flannel,  after  which  she  revives  to  some  extent. 

18th  December  1907. — Improvement  has  been  progressive.  She  has  taken  some 
milk  and  some  slices  of  pear  and  apple.  The  swelling  has  almost  entirely  dis- 
appeared from  the  upper  limbs,  but  she  is  still  very  weak  and  unable  to  stand  up  on 
her  hind  limbs.  The  hands  seem  heavy  as  she  raises  them  to  take  a  small  piece  of 
sugar.  Respiration  is  no  longer  difficult,  but  the  heart-beats  are  still  abnormally 
frequent. 

23rd  December  1907. — General  condition  still  further  improved,  but  she  is  inactive 
and  depressed.  Urged  to  leave  her  couch,  she  rises  and  makes  a  few  steps,  but  is 
completely  dysorientated,  does  not  know  where  to  go,  moving  now  to  the  right,  now 
to  the  left  in  an  uncertain  fashion.  Sometimes  her  hands  or  her  feet  are  bent  under 
so  that  she  walks  on  the  back  of  them  (paresis),  then,  as  she  continues  to  walk,  she 
straightens  them  out.  It  is  not  yet  opportune  to  proceed  with  the  methodical 
examination  of  her  mental  state. 

28th  December  1907. — She  walks  well  and  no  longer  supports  herself  on  the 
dorsum  of  the  hands.  She  turns  to  right  or  to  left  by  chance,  or  when  shown  some- 
thing to  eat.  She  presents  a  slight  inward  curvature  of  the  trunk,  but  at  times 
stands  erect  on  her  feet.  The  eyes  being  covered  with  sub-palpebral  eye-shades  of 
caoutchouc,  we  proceed  to  the  examination  of  sensibility,  which  is  found  to  be  well 


176  THE  MECHANISM  OF  THE  BRAIN 

preserved  in  every  part  of  the  body.     She  always  shakes  herself  when  touched 
unawares. 

Hearing,  tested  in  the  usual  way  with  the  tuning-fork,  is  well  preserved. 

The  examination  of  sight,  one  or  other  eye  being  covered,  leaves  some  doubt  as 
to  its  precision  as  regards  recognition  of  objects  placed  successively  in  front  of  her, 
and  as  to  the  clearness  and  distance  of  vision,  inasmuch  as  she  makes  mistakes  in 
her  movements  of  prehension.  On  suspending  a  piece  of  sugar  by  a  thread,  and 
making  it  pass  from  without  inwards  opposite  each  eye,  on  a  horizontal  plane  at  the 
level  of  the  visual  axis,  she  turns  her  eye  upon  the  object  as  soon  as  it  enters  the 
normal  visual  field,  but,  although  hungry,  does  not  always  extend  her  hand  to 
grasp  it.  She  seems  torpid  and  indifferent,  and  puts  out  her  hand  slowly,  and  does 
not  always  measure  distance  with  precision.  She  has  lost  her  vivacity,  her 
craftiness,  and  the  lightning  rapidity  of  the  movements  of  her  right  hand.  The 
condition  is  identical  on  both  sides. 

If,  when  left  to  her  own  devices,  she  comes  to  a  halt  anywhere  in  the  room  and  I 
throw  a  piece  of  sugar  very  near  her,  either  to  her  right  or  to  her  left,  she  takes  it 
and  puts  it  in  her  mouth.  If  I  throw  it  some  distance  off  she  makes  a  run  after  it, 
then  seems  to  lose  sight  of  it,  stops  half-way,  as  though  she  had  forgotten  about  it, 
gives  up  the  search  and  takes  another  direction.  Possibly  her  accommodation  is  de-  • 
fective,  but  it  is  very  difficult  to  decide  whether  we  have  to  deal  with  visual  accom- 
modation or  with  defect  of  mental  accommodation  based  on  memory  and  attention. 

8th  January  1908. — Her  physiognomy  seems  altered.  It  has  lost  that  lively 
glance,  that  air  of  scrutinising  and  crafty  curiosity  that  was  so  characteristic  of  this 
monkey.  She  walks  about  the  room,  where  she  is  kept  under  observation,  for 
several  hours  together.  Sometimes  she  stops  and  picks  up  morsels  of  bread  and 
small  pieces  of  chalk  thrown  down  together.  She  puts  everything  in  her  mouth. 
She  halts  in  front  of  a  yellow  spot  on  the  wall,  touches  it  and  retouches  it,  as  though 
she  wished  to  pick  out  the  plaster  with  her  finger.  She  jumps  up  on  the  window- 
ledge  as  usual,  but  does  not  give  the  call ;  she  remains  there,  indifferent,  with  her 
head  bent,  for  several  minutes,  then  comes  down  again.  She  shakes  and  jumps  at 
every  noise  and  crouches  in  a  corner,  where  she  remains  for  a  considerable  time  with 
head  bent.  Then  she  gets  up,  raises  her  head,  and  passes  and  repasses  more  than  a 
dozen  times,  in  stereotypic  fashion,  between  the  wall  and  the  door.  She  does  not 
trouble  about  me,  nor  does  she  seek  to  come  on  to  my  table,  as  she  was  so  keen  to  do 
prior  to  the  operation.  I  have  given  her  a  small  box  with  one  side  made  of  glass 
through  which  she  can  readily  see  its  contents — viz.  two  apples.  She  has  taken  it, 
has  turned  arid  returned  it  over  in  her  hands.  She  has  tried  to  put  her  fingers 
through  the  glass  to  take  the  apple,  then  has  put  her  nose  and  lips  to  the  glass.  She 
makes  off,  with  the  box  in  her  hand,  to  a  corner  of  the  room  where  she  sits  on  her 
hind  quarters  for  several  minutes,  keeping  the  box  in  her  hands,  rotating  it  between 
her  fingers,  but  making  no  attempt  to  open  it. 

24:ih  January. — Death  occurred  this  evening  as  the  result  of  an  accident. 

Post-mortem  examination  nine  hours  after  death.  On  laying  bare  the  cranium 
nothing  of  note  is  observed  except  the  two  breaches  in  the  frontal  lobes,  now  closed 
by  cicatrices.  Apart  from  two  pearly  spots  corresponding  to  the  breaches,  the 
meninges  are  perfectly  healthy.  The  brain,  when  removed  and  subjected  to  an 
accurate  inspection,  appears  normal  in  colour,  without  sign  of  any  lesion  with  the 
exception  of  the  experimental  inj  nries  to  the  frontal  lobes.  These  seem  almost  sym- 
metrical. On  the  right  side,  the  lesion  in  the  first  convolution  extends  behind  to 
within  almost  3  cm.  from  the  upper  extremity  of  the  Rolandic  fissure.  In  its  middle 
portion  it  reaches  the  anterior  margin  of  the  pre-Rolandic  convolution.  Below, 
the  operculum  of  the  second  convolution  is  injured,  but  there  remains  a  small  bridge 
by  means  of  which  it  is  continuous,  below,  with  the  orbital  surface  of  the  frontal 
lobe,  which  is  perfectly  preserved,  and,  posteriorly,  with  the  operculum  of  tho 
anterior  Rolandic  convolution. 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS    177 

The  pole  of  the  frontal  lobe  is  preserved,  and  is  continuous  with  the  first  frontal 
convolution  by  means  of  a  bridge  which  forms,  as  it  were,  a  vault  hiding  the  lesion 
which,  underneath,  reaches  the  internal  surface  of  the  hemisphere,  doing  injury  at 
one  point  to  the  first  convolution  and  the  convolution  of  the  corpus  callosum  just 
over  the  genu  of  the  latter,  which  is  intact. 

On  the  left  hemisphere  the  lesion  is  almost  symmetrical.  The  frontal  and  pre- 
frontal  portion  lying  in  front  of  the  pre-frontal  sulcus  is  almost  completely  removed. 
The  pole  is  fairly  well  preserved,  and  is  continuous  with  the  rest  of  the  cerebrum 
only  on  the  orbital  surface,  which  appears  normal.  The  first  frontal  convolution  on 
the  interhemispheric  aspect  is  interrupted  by  the  experimental  incision,  which 
reaches  in  depth  to  the  convolution  of  the  corpus  callosum  one  millimetre  in  front 
of  the  germ  of  the  latter.  Below  and  without,  the  lesion  reaches  almost  to  the 
external  margin  of  the  orbital  surface. 

On  each  side  the  whole  of  the  orbital  surface  of  the  frontal  lobe  is  spared,  along 
with  a  zone  of  the  external  surface  more  than  one  centimetre  in  length,  by  means  of 
which  the  orbital  surface  is  continuous  with  the  pre-Rolandio  operculum. 

This  observation  is  interesting,  because  it  provides  another  illustration  of  the 
fact  that  it  is  very  difficult  to  destroy  and  remove  all  the  frontal  lobe,  without 
making  a  very  large  breach  and  laying  bare  the  whole  field  of  operation.  In  the 
latter  case,  however,  the  operation  is  a  much  longer  one,  and  in  my  experience  small 
monkeys  do  not  survive  it.  Even  this  monkey  passed  through  a  phase  of  excep- 
tional gravity  lasting  several  days,  and  it  was  only  by  assiduous  care  and  attention 
that  we  succeeded  in  keeping  it  alive.  What  generally  happens  is  that  the  opening 
in  the  cranium  is  made  rather  far  in  front,  so  that  one  can  detach  the  pole  and 
decorticate  a  tract  of  what  remains  behind,  in  which  case  a  considerable  portion  of 
the  frontal  lobe  is  left :  or,  on  the  other  hand,  one  exposes  the  excitable  frontal  area 
along  with,  a  little  of  the  Rolandic  convolution  suitable  for  making  observations  on 
the  electric  excitability,  and  in  this  case  the  lateral  limits  and  the  pole  of  the  frontal 
lobe  remain  covered  so  that  a  part  of  the  frontal  lobe  remains  in  anatomical  relation 
with  the  Rolandic  brain  and  Avhat  lies  behind  it.  As  it  is  important  that  the  animal 
operated  upon  should  be  kept  alive,  one  has  to  avoid  prolonging  the  operation 
to  any  great  extent,  or  making  the  cranial  opening  too  large. 

EXPERIMENT  12.—  Monkey  D.— The  largest  of  the  tribe.  Strong,  alert  and  bold. 
If  I  approach  the  cells  of  the  other  monkeys  and  take  any  of  them  by  the  hand,  he 
spies  me  from  his  own  little  cell,  becomes  agitated  and  angry,  shakes  his  chain  with 
both  hands,  and  watches  me  with  a  threatening  air  and  leonine  haughtiness,  as 
though  it  fell  to  him  to  look  after  the  interests  of  all  the  other  monkeys.  If  one 
remains  in  front  of  the  cell  in  an  antagonistic  or  threatening  attitude  he  falls  back  a 
pace  or  two,  opens  his  mouth  and  shows  his  teeth,  or  he  springs  at  the  gate  and 
shakes  it  in  a  threatening  and  irate  manner.  If  he  gets  possession  of  a  piece  of  bread 
or  small  stone  he  hurls  it  at  one.  If  another  monkey  is  led  away  to  the  observation- 
room,  he  assumes  the  air  of  a  protector,  peers  out  in  an  angry  manner,  hurls 
himself  against  the  iron  bars,  shaking  them  in  his  rage,  and  sometimes  calling  out. 

23rd  December  1907. — Along  with  other  pieces  of  apple  I  give  him  one  dipped  in  a 
solution  of  quinine.  He  at  once  notices  the  difference.  When  he  takes  it  he  ex- 
amines it  carefully,  smells  it,  looks  at  me  with  suspicion,  rubs  it  with  some  straw, 
and  on  the  wall  of  his  cell,  and  after  this  operation  brings  it  to  his  lips  again,  finds 
that  it  is  still  bitter,  throws  it  away,  then  takes  the  straw  in  both  hands,  tossing  it 
several  times  into  the  air,  as  though  to  give  vent  to  his  rage.  As,  however,  he  has 
keen  kept  without  food  for  some  time,  and  is  rather  hungry,  he  again  picks  up  the 
piece  of  apple,  breaks  it,  and,  exercising  great  care  and  caution,  eats  the  central  part. 

I  place  a  piece  of  apple  on  a  large  stone  lying  in  front  of  his  cell,  just  beyond 
reach  of  his  hands.  After  many  futile  attempts  to  reach  it  he  decides  to  move  the 
M 


178  THE  MECHANISM  OF  THE  BRAIN 

stone  cautiously,  with  the  evident  object  of  bringing  it  nearer  him  without  allowing 
the  apple  to  fall.  I  now  fix  an  apple  to  a  ribbon  and  suspend  it  in  front  of  his  cell, 
at  a  distance  slightly  greater  than  the  length  of  his  arm.  He  makes  every  effort  to 
reach  it,  but  always  falls  short  of  it  by  about  4  or  5  cm.  Seeing  the  futility  of  his 
attempts  he  gives  them  up,  squatting  down  with  his  hands  crossed,  between 
mortification  and  irritation. 

J  now  make  the  apple  swing  like  a  pendulum.  On  the  second  oscillation  he 
clutches  it  with  marvellous  rapidity  and  precision.  He  draws  in  the  ribbon  with  it 
to  the  bottom  of  his  cell,  and,  after  having  eaten  the  apple,  plays  with  the  ribbon. 
In  vain  I  seek  to  get  it  from  him.  I  hold  an  apple  before  him  in  one  hand,  and  put 
out  the  other  hand  in  the  attitude  of  one  asking  something.  After  twice  calling 
loudly  to  him  he  has  rolled  up  the  ribbon  and  thrown  it  to  me.  I  pick  it  up  and  give 
him  an  apple  in  exchange.  I  put  an  apple  on  the  top  of  a  stone,  at  some  distance 
from  him.  Strong  as  he  is,  he  reaches  through  the  bars  and  tries  to  shake  the  stone 
so  as  to  make  the  apple  fall.  Failing  in  this,  he  gives  up  the  attempt.  I  give  him  a 
spindle  off  a  chair.  He  plays  with  it,  turning  it  round  in  his  hands.  Whilst  he 
still  has  it  in  his  hand  I  chase  him  out  of  the  cell.  With  it  he  could  have  knocked 
down  the  apple,  but  he  has  not  been  capable  of  this  reasoning  process.  He  has, 
however,  thrown  the  spindle  in  the  direction  of  the  apple  which,  in  point  of  fact,  has 
actually  fallen,  though  I  remain  in  doubt  as  to  whether  this  was  a  chance  affair  or 
the  result  of  reasoning. 

I  wrap  pieces  of  apple  in  red,  and  pieces  of  chalk  in  blue,  paper.  After  four  trials 
he  has  not  shown  any  sign  of  remembrance  that  the  blue  contain  chalk  and  the  red 
apple  (has  he  failed  to  perceive  the  difference  between  the  colours,  or  is  it  that  he 
has  not  remembered  ?). 

8th  January  1908. — I  give  him  a  long  stick  which  has  been  applied  to  him  several 
times  as  an  instrument  of  correction.  At  first  he  bites  it,  then  he  plays  with  it.  As 
there  is  an  apple  on  a  stone  at  some  distance  off,  he  throws  the  stick  so  that  it  falls 
on  that  stone.  The  apple  falls  down,  and,  with  lightning  rapidity,  he  throws  him- 
self on  it  and  seizes  it  with  his  hand.  At  the  same  time  I  dart  forward  to  lay  hold  of 
the  stick  and  keep  it  out  of  the  cell,  but  the  monkey,  with  the  rapidity  of  a  leopard, 
seizes  it  with  his  other  hand  and  draws  it  away  into  his  cell  before  I  can  reach  it. 

He  is  next  transferred  into  a  large  cage  made  of  wooden  bars  arranged  very  close 
to  one  another.  An  apple  is  now  placed  near  the  cage  and  he  tries  to  put  his  hand 
and  wrist  through  the  different  spaces  between  the  bars,  trying  one  space  after 
another  until  he  finds  one  large  enough  to  allow  him  to  get  his  hand  through  and 
grasp  the  apple.  When  he  gets  it,  he  finds  that  the  space  is  not  wide  enough  to  let 
the  apple  pass  through.  He  becomes  agitated  and  tries  all  the  spaces,  putting  his 
feet  against  the  wooden  bars  and  trying  to  forcibly  pull  the  apple  through.  This 
plan  not  succeeding,  ho  bites  the  apple  all  round,  with  the  apparent  object  of  making 
it  smaller  so  as  to  let  it  pass  between  the  bars  of  the  cage, 

I  put  pieces  of  apple  in  a  narrow-necked  bottle  which  I  give  to  him.  Immedi- 
ately he  gets  it  he  tries  all  he  can  to  get  out  the  pieces  of  apple,  showing  great 
interest  and  anxiety  in  the  process,  turning  and  returning  the  bottle  and  biting  it. 
After  many  attempts  he  breaks  the  bottle  and  eats  the  pieces  of  apple. 

I  put  two  apples  in  a  little  tin  box  with  a  little  glass  window.  I  have  hardly 
given  it  to  him  when,  in  the  twinkling  of  an  eye,  he  breaks  into  it  with  his  teeth. 

I  relate  the  psychological  data  of  this  monkey  because  they  serve  to  give  a 
certain  measure  of  the  intelligence  and  emotions  of  this  kind  of  quadrumane,  and  to 
furnish  still  another  proof  of  the  necessity  for  a  full  examination  of  these  animals, 
both  before  and  after  the  operation.  Unfortunately  this  strong,  intelligent  and 
masterful  monkey  died  in  less  than  twenty-four  hours  after  operation. 

EXPERIMENT  13. — 8th  March  1908. — Monkey  E.  Male.  Anaesthesia  by  chloro- 
form after  previous  injection  of  morphine.  Bilateral  trepanning  without  serious 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS    179 

difficulty  and  without  loss  of  blood.  Section  and  reflection  of  the  dura  mater. 
Electric  excitation  of  a  small  area,  3  mm.  in  diameter,  situated  2  or  3  mm.  in  front 
of  the  limits  of  the  area  of  excitation  of  the  anterior  limb,  produces  dilatation  of  the 
pupils,  more  especially  that  of  the  opposite  side.  Further  upwards  and  inwards, 
excitation  produces  conjugate  movements  of  the  eyes.  Still  further  inwards,  on 
the  foot  of  the  first  frontal  convolution  near  the  interhemispheric  margin,  excitation 
gives  rise  to  movements  of  the  head  to  the  opposite  side.  A  few  millimetres  below 
the  area  for  dilatation  of  the  pupil  there  is  a  small  excitable  area  related  to  the 
opposite  ear. 

With  the  thermo-cautery  at  red  heat,  I  incise  the  frontal  lobe  (first  and  second 
convolutions)  along  the  pre-frontal  sulcus,  to  the  depth  of  at  least  one  centimetre,  on 
both  sides.  No  troublesome  incident.  Suture  of  the  dura  mater  and  of  the  other 
parts,  and  the  usual  dressing  with  iodoform  and  collodion. 

9th  March  1908.— No  accident. 

lllh  March  1908. — He  is  fairly  lively.  He  can  grasp  pieces  of  apple  or  chestnuts 
equally  well  with  either  hand.  He  clambers  up  the  bars  of  the  cage.  The  pupils 
are  equal.  Winking  is  normal.  He  sees  near  at  hand,  and  grasps  pieces  of  bread 
or  apple,  but  he  does  not  see  at  a  distance.  He  does  not  see  an  apple  placed  on  the 
ground  two  metres  off. 

Tactile  sensibility  is  normal. 

Both  monkey  E  and  the  female  monkey  G,  which  had  previously  undergone 
operation  on  one  side,  are  now  taken  from  their  cages  and  left  together.  E  im- 
mediately attempts  copulation  with  G,  his  movements  being  quite  normal,  but 
he  seems  afraid,  and  the  attempt  is  hardly  begun  before  it  is  given  up.  Shortly 
afterwards  he  curls  himself  up,  lowers  his  head  and  appears  to  sleep. 

loth  March  1908. — The  wound  is  healing  satisfactorily  by  first  intention.  There 
is  no  suggestion  of  suppuration.  There  is  no  sign  of  paralysis  in  the  trunk,  neck  or 
limbs.  He  walks,  jumps,  grasps  with  both  hands,  and  masticates  as  though 
nothing  had  happened  to  him;  indeed,  just  as  he  did  prior  to  the  operation.  He 
does  not  perceive  objects  with  precision  and  certainty  at  a  distance,  but  this 
symptom  was  more  marked  in  the  first  days  after  the  operation.  He  shows  a  fair 
amount  of  boldness  in  looking  around  the  room  for  food  even  when  chased  away 
from  it.  Tactile  sensibility  is  perfectly  preserved.  If,  when  his  eyes  are  covered, 
the  ear  is  lightly  touched,  he  immediately  shakes  his  head  as  under  normal  con- 
ditions. Vision,  which  in  the  first  few  days  was  very  defective,  is  now  much  more 
precise.  Fear  is  always  a  marked  symptom.  Clapping  the  hands,  even  after 
numerous  repetitions,  produces  a  strong  trembling  of  the  whole  body. 

He  goes  about  the  room  in  a  rambling,  dysorientated  fashion.  If  given  a  piece 
of  bread  dipped  in  a  weak  solution  of  quinine  he  notices  its  bitter  taste,  is  very 
doubtful  about  masticating  it,  then  ends  by  rejecting  it  from  his  mouth  (the  female 
selects  from  the  bread  that  part  which  has  not  been  soaked  with  the  quinine).  The 
bitter  taste  of  a  piece  of  apple  immersed  in  quinine  solution  is  certainly  detected  by 
the  mpJe,  but  rather  more  readily  by  the  female.  The  former  has  eaten  it  reluctantly, 
the  latter  after  two  trials  has  definitely  rejected  it. 

A  good  deal  passes  unobserved  under  his  eyes.  If  he  changes  his  position  from 
one  corner  to  another  of  the  room,  it  is  without  aim  or  purpose.  He  seems  in- 
different quite  as  much  as  dysorientated.  If  an  apple  is  thrown  on  the  floor  he 
sometimes  runs  after  it.  At  other  times  he  loses  trace  of  it,  no  matter  how  short  its 
distance  from  him,  as  though  he  either  forgot  to  continue  running  after  it  or  else  did 
not  see  it.  The  female  runs  after  it  to  any  distance  and  picks  it  up.  E  readily 
recognises  the  persons  who  are  in  the  habit  of  bringing  him  food,  and  sometimes 
follows  them  as  though  expecting  something  to  eat,  but  beyond  this  shows  no  other 
sign  of  mental  activity. 

Sometimes  he  picks  up  straw  or  other  small  and  insignificant  objects — e.g.  a 
thread  or  a  piece  of  crumpled  paper — so  that  he  reminds  one  of  the  tendency  to 


180  THE  MECHANISM  OF  THE  BRAIN 

collect  useless  objects  that  is  so  marked  in  some  dements.  It  is  certainly  a  thing 
he  never  did  before.  The  feature  that  is  most  prominent  is  his  loss  of  courage.  He 
no  longer  reacts  as  before,  no  matter  what  one  does  to  him — e.g.y  when  one  snatches 
an  apple  out  of  his  hand,  although  he  formerly  reacted  with  a  courage  and  vigour 
that  were  truly  impressive,  even  when  shut  in  his  cage.  He  no  longer  calls  out  to 
his  companions  as  in  the  past.  If  offered  some  morsels  of  sugar,  they  must  fall 
within  the  visual  field  of  the  eye  and  within  reach  of  his  hand ;  otherwise  he  either 
fails  to  see  them,  or,  if  he  does  see  them,  neglects  to  take  them ;  once  he  has  taken 
them,  however,  he  eats  them  with  relish.  If,  on  the  other  hand,  one  throws  him  a 
piece  of  chalk,  he  breaks  off  a  bit  with  his  teeth  and  keeps  the  fragments  a  long  time 
in  his  mouth.  He  notices  the  difference,  and  remains  with  the  other  piece  in  his 
hand.  If,  after  half  an  hour,  the  experiment  with  the  chalk  is  repeated,  he  does  not 
remember  the  previous  experience  and  again  he  tastes  it,  biting  off  a  piece,  and 
keeping  the  rest  a  long  time  in  his  hand,  or  letting  it  fall,  whilst  before  the  operation 
it  was  sufficient  for  him  to  taste  the  chalk  once  and  for  all  before  he  threw  it  into 
the  air,  or  squashed  it  in  pieces  on  the  floor,  never  again  to  fall  into  the  same  trap. 

8th  April  1908. — There  is  no  marked  sign  of  defect  of  motor  function  or  of  special 
sensibility.  The  visual  field  is  not  apparently  diminished.  The  monkey  notices  a 
piece  of  apple  suspended  to  a  thread  and  allowed  to  come  within  the  extreme  limit 
of  the  visual  field  either  from  the  right  or  the  left,  and  grasps  it  with  rapid  and 
certain  movements  that  betray  no  noticeable  difference  between  the  two  sides. 
Only  occasionally  has  it  seemed  that  vision  was  less  clear  on  the  right  side.  There 
is  no  difference  in  the  size  of  the  pupils.  There  is  a  hardly  noticeable  difference  in 
the  motility  of  the  upper  limbs,  in  the  sense  that  he  makes  more  use  of  the  left ;  but 
in  all  operations  necessitating  the  use  of  both  hands,  as  in  forcibly  pulling  an  apple 
through  the  space  between  the  bars  of  the  cage,  he  makes  very  good  use  also  of  the 
right  hand,  with  which  he  executes  movements  that  are  as  precise  as  those  of  the 
left. 

25th  April  1908. — He  is  brought  into  the  room  without  a  chain.  He  is  very 
docile  and  timid.  He  has  lost  the  alacrity,  vivacity,  aggressiveness  and  boldness 
which  so  characterised  his  actions  in  the  past.  He  moves  about  the  room  very 
indifferent,  or  remains  curled  up  a  long  time  in  one  spot,  perhaps  in  a  corner, 
without  manifesting  care  or  concern  about  anything,  showing,  above  all  else,  a 
2jreat  lack  of  that  spirit  of  observation,  suspiciousness  and  craftiness  which  is  so 
characteristic  of  the  mental  life  of  these  quadrumanes. 

Visual  sensibility  is  undamaged.  If,  however,  a  piece  of  fruit  or  bread  is  placed 
three  or  four  metres  in  front  of  him  he  gives  no  sign  of  having  realised  that  it  is 
there  (disattention  or  lack  of  accommodative  power  ?). 

I  now  report  a  series  of  comparative  experiments  made  with  other  two  monkeys 
F,  a  male,  intact ;  G,  a  female,  operated  upon  on  one  side  only. 

Monkey  E  remains  indifferent,  or  wanders  aimlessly  about  the  room,  or  performs 
purposeless  movements,  paying  no  heed  to  the  female,  which  is  calling  out  and 
making  a  great  noise  in  her  cage  on  the  terrace. 

Monkey  G  is  now  brought  into  the  room  and  E  is  taken  to  his  cage.  G  is  evi- 
dently greatly  concerned.  She  jumps  up  on  the  window-ledge  to  see  where  E  is, 
and  exerts  herself  in  every  possible  way,  spying  out  of  the  window  with  great 
anxiety. 

Monkey  E  is  restless  and  excited,  and,  if  he  sees  a  piece  of  apple  or  bread,  he 
becomes  agitated  and  clambers  up  the  iron  bars  of  his  cage,  performing  all  sorts  of 
antics.  I  offer  him  a  slice  of  apple.  He  puts  out  his  hand  to  take  it,  and  at  the 
same  moment  I  hide  it  by  shutting  my  hand,  letting  him  take  hold  of  my  forefinger 
instead.  Forgetful  of  the  deceit  so  often  practised  upon  him  he  anxiously  seizes  my 
hand,  trying  to  force  his  own  hand  into  my  closed  fist,  in  order  to  get  hold  of  the 
apple,  and  he  obstinately  persists  in  the  attempt,  at  the  same  time  trembling  all 
over.  The  other  male  monkey,  F,  acts  differently,  for  once  he  is  cheated  he  makes 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS    181 

no  second  attempt,  despite  the  fact  that  I  display  the  apple,  holding  it  between  my 
fingers,  so  near  to  him  that  he  could  easily  get  possession  of  it.  His  attitude  sug- 
gests a  dignified  indifference,  so  much  so  that  one  might  well  argue  that  he  feels 
offended  at  the  deception.  No  matter  how  often  I  offer  the  piece  of  apple  to  E 
and  cheat  him  in  the  manner  described,  so  often  does  E  fall  stupidly  into  the  same 
trap.  He  has  learned  nothing  from  the  deceptions  practised  upon  him  at  brief 
intervals. 

When  the  two  males  are  taken  out  of  their  cages  and  left  together,  the  small 
monkey  F  pays  court  to  the  big  monkey  E,  running  behind  him  and  making  attempts 
at  copulation.  E  accepts  and  endures  the  caresses  of  the  other  without  evincing 
any  sign  of  affection.  Occasionally  he  seems  to  go  into  ecstasy  when  F  and  G 
commence  insect-hunting  operations  upon  him,  or  stroke  the  skin  of  his  neck. 

If  now  I  throw  three  or  four  pieces  of  fruit  on  the  ground  quite  near  to  E,  the 
other  two,  F  and  G,  immediately  hurl  themselves  on  the  booty,  using  hands  and 
feet  to  seize  as  much  as  they  can.  E  makes  an  attempt  to  get  hold  of  a  piece  which 
is  very  near  him,  but  so  torpid  and  slow  is  he  that  he  is  forestalled  by  his  com- 
panions and  remains  with  empty  hands.  This  experiment  brings  very  clearly  into 
evidence  a  defective  judgment,  because  he  does  not  foresee  that  his  two  companions 
might  get  possession  of  all  the  fruit  before  he  has  managed  to  secure  a  piece  for 
himself.  He  has  made  no  use  of  past  experience  (defect  of  memory,  imagination 
and  judgment  concerning  this  form  of  struggle  for  life),  as  compared  with  the  alert 
rapidity  of  the  other  two.  There  is  also  evident  a  defect  in  the  motor  discharge,  so 
that  his  movement  is  more  torpid,  slower  and  all  in  vain.  If  not  specially  taken 
care  of  and  fed  he  would  have  succumbed,  owing  to  his  incapacity  to  compete 
efficaciously  with  the  others  in  assuring  for  himself  the  necessities  of  existence. 

Pretty  much  the  same  thing  happens  with  human  imbeciles  (if  not  cared  for  and 
protected),  who  are  quite  unfitted  for  the  struggle  for  existence. 

10th  May  1908. — E  has  become  aggressive,  revengeful  and  voracious.  If, 
shortly  after  he  has  been  enjoying  the  caresses  of  the  female  monkey  G,  I  give  the 
latter  a  piece  of  apple,  he  endeavours  to  snatch  it  from  her.  Failing  in  this,  because 
G  is  in  her  cage,  he  seizes  her  tail  and  bites  it,  and  then  grasps  her  by  the  back  in 
order  to  take  the  apple  from  her.  G,  full  of  cunning,  puts  the  apple  in  her  mouth, 
and  with  both  hands  liberates  herself.  This  scene  has  been  repeated  several  times. 
E  also  hurls  himself  against  the  other  male.  Every  sentiment  seems  overruled  by 
that  of  voracity,  so  that  he  has  become  impulsive  and  aggressive. 

I  throw  to  E  a  piece  of  apple  wrapped  in  blue  paper.  He  makes  no  effort  to 
take  it,  and  does  not  move  from  his  position.  I  pick  it  up  and  put  it  just  under  his 
nose.  He  takes  it,  unwraps  it,  and  eats  the  apple  with  relish.  Shortly  afterwards 
he  takes  the  blue  paper,  masticates  it  and  swallows  a  piece,  a  thing  which  none  of 
the  normal  monkeys  under  my  observation  has  ever  done.  I  throw  a  similar  packet 
to  G,  at  some  distance  off  from  her.  She  goes  after  it  wherever  it  lands,  unwraps  it 
and  eats  the  content. 

I  place  a  plate  of  apples  on  the  top  of  a  high  bookcase.  E  makes  no  attempt  to 
reach  it.  G,  on  the  contrary,  makes  repeated  attempts,  and  tries  in  every  possible 
way  to  reach  it.  She  fails,  but  this  is  because  of  the  smooth  surface  and  glass  doors 
of  the  bookcase.  A  chair  is  now  brought  close  up  to  the  bookcase.  E  pays  no 
heed  to  this,  notwithstanding  the  fact  that  he  has  eaten  very  little.  G  jumps  up 
on  to  the  back  of  the  chair  and  tries  to  spring  up  to  the  bookcase  to  get  the  apples. 

In  general  E  is  dysorientated,  remiss  and  stupid  in  behaviour.  He  exhibits  no 
spirit  of  enterprise,  no  boldness.  The  behaviour  of  G,  on  the  contrary,  is  that  of 
one  who  moves  with  definite  aims  which  are  in  the  domain  of  actual  perceptions, 
one  who  formulates  judgments  on  the  basis  of  memory  and  experience,  making  use 
of  all  new  contingencies  in  order  to  arrive  at  the  object  in  view. 

2Qth  May  1908. — Monkey  G  (first  operation,  8th  March).  An  opening  is  now 
made  in  the  cranium  on  the  other  side,  the  usual  technique  being  employed.  Save 


182  THE  MECHANISM  OF  THE  BEAIN 

for  some  little  haemorrhage,  the  operation  is  free  of  any  incident.  Electric  excita- 
tion in  front  of  the  ascending  frontal  convolution  at  some  considerable  distance  from 
the  area  of  excitation  of  the  anterior  limb  has  produced: — (1)  Movement  of  the 
ocular  bulbs  towards  the  opposite  side.  (2)  At  a  point  slightly  higher  up,  move- 
ment of  the  head  towards  the  opposite  side.  (3)  Rather  more  upwards  and  inwards, 
more  marked  movements  of  the  head  to  the  opposite  side  and  backwards. 
(4)  Lower  down,  under  the  area  for  movements  of  the  eyes,  movements  of  the 
ears,  more  marked  in  the  ear  of  the  opposite  side. 

The  cortex  of  that  part  of  the  frontal  lobe  lying  in  front  of  this  excitable  area  is 
now  removed. 

Aseptic  suture. 

30th  May  1908. — Four  days  have  been  allowed  to  elapse  before  taking  observa- 
tions. The  monkey  is  now  brought  into  the  observation-room,  and  allowed  com- 
plete freedom.  She  hides  under  a  couch,  and  there  moves  backwards  and  forwards 
from  one  end  to  the  other,  always  in  the  same  fashion,  in  an  aimless  way,  as  though 
unconscious  of,  and  indifferent  to,  everything  and  everyone  in  the  room.  At  length 
she  comes  out,  sees  the  handle  of  the  door  which  leads  on  to  the  terrace  where  her 
companions  are,  and  makes  numerous  obstinate  attempts  to  clamber  up  the  door 
so  as  to  reach  the  handle  and  open  it.  She  jumps  and  clambers  up,  seizes  the 
handle,  sits  on  it,  and  soon  comes  down  again  to  begin  the  process  anew,  always 
going  through  the  same  movements  in  the  same  rhythmical  stereotyped  fashion, 
perhaps  ten  or  twelve  times,  reminding  one  of  a  tic  or  automatism. 

3(M  May  1908.— Monkey  F,  male,  intact.  Smaller  than  E.  He  is  brought 
into  the  examination-room  secured  by  his  chain.  He  is  circumspect,  he  jumps  up 
on  the  furniture  to  see  what  there  is  around.  He  makes  a  tour  of  inspection  of  the 
room.  He  even  jumps  up  to  the  window-ledge  to  spy  out  the  terrace  where  the 
other  monkeys  are,  and  to  them  he  makes  calls.  He  sees  a  piece  of  bread  placed  on 
the  top  edge  of  the  bookcase,  and  seeks  with  adequate  movements  to  jump  up  to 
get  possession  of  it.  After  two  failures  he  gives  up  the  attempt. 

He  takes  hold  of  pieces  of  bread  or  apple  with  rapidity  and  precision  in  his 
movements,  getting  at  them  even  in  difficult  positions,  unless  they  are  closely 
guarded.  When  one  makes  evident  signs  of  deterring  him,  he  pretends  to  have 
abandoned  the  undertaking,  only  to  seize  any  moment  of  distraction  on  the  part  of 
the  person  who  has  made  signs  of  intervention,  when  he  draws  near  with  great 
cunning,  seizes  the  object  of  his  desire,  and  retreats  with  much  precaution. 

His  movements  in  all  their  variety  show  a  finality  quite  closely  resembling  those 
of  an  erethistic  imbecile,  who  overcomes  many  obstacles  so  long  as  the  quest  of  food 
is  involved. 

At  intervals  of  fifteen  minutes  small  red  paper  packets  are  thrown  to  him,  the 
first  containing  a  piece  of  chalk,  the  second  a  piece  of  apple  previously  immersed  in 
solution  of  quinine,  the  third  a  piece  of  chalk.  He  unwraps  the  first  packet,  re- 
cognises the  chalk  after  testing  it,  and  rejects  it.  On  the  second  occasion  he  tastes 
and  tests  the  bitter  apple,  examines  it  several  times,  retastes  it,  and  ends  by  throwing 
it  away.  On  the  third  trial,  though  hungry,  he  remains  indifferent,  allowing  the 
packet  to  lie  on  the  ground,  and  pays  no  heed  to  it,  although  he  passes  close  by  it 
several  times. 

Monkey  E.  Comparative  experiments  with  F  (male)  and  G  (female).  Those 
three  monkeys  are  placed  together.  E  and  G  are  indifferent  to  one  another,  and 
both  show  indifference  towards  the  third. 

F  follows  them  about  for  a  little  as  though  to  make  friends.  On  seeing  himself 
deceived  by  the  indifference  of  the  other  two,  he  jumps  up  on  the  window-ledge, 
peeps  out,  and  makes  calls.  Even  to  these  calls  the  other  two  remain  indifferent. 
The  one  passes  to  and  fro  from  one  wall  to  another  along  the  same  track.  The 
second  remains  near  a  wall,  repeatedly  touching  a  small  spot  with  his  forefinger,  as 
though  desirous  of  removing  it.  I  throw  some  cherries  and  pieces  of  medlar  on  the 


EXPEKIMENTAL  HISTORIES  OF  DOGS,  FOXES  £  MONKEYS    183 

ground.  F  jumps  down  from  the  window,  and  with  both  hands  and  feet  gathers 
up  as  many  of  these  as  he  can,  stuffing  his  mouth  with  them  with  extraordinary 
rapidity.  The  other  two  monkeys  run  forward,  but  they  are  torpid  and  slow  in 
their  movements,  and  manage  only  to  pick  up  what  is  left  by  F.  In  fact,  had  I  let 
fall  on  the  ground  only  four  or  five  cherries,  the  two  mutilated  monkeys  might 
possibly  have  picked  up  one,  but  just  as  possibly  none  at  all,  notwithstanding  the 
fact  that  F  (the  normal  monkey)  was  posted  on  the  window  at  a  greater  distance 
away.  I  throw  some  pieces  of  plaster  on  the  ground.  At  the  noise  and  sight  of 
these  the  two  run  forward,  awkwardly  as  usual,  pick  up  some  pieces  and  stand  there, 
uncertain  whether  or  not  to  put  them  in  their  mouths.  F  does  not  even  move  from 
the  window-ledge,  but  looks  on  with  an  air  of  curiosity  at  the  behaviour  of  the  other 
two  (rapidity  of  perception  and  precision  of  judgment).  He  has  perceived  the  form 
of  the  pieces  of  plaster  and  has  noticed  that  the  noise  they  make  is  very  different 
from  that  caused  by  the  falling  of  fruit  on  the  ground. 

What  is  particularly  surprising  is  the  fact  that  F  no  longer  cares  to  associate 
with  E  and  G,  who  have  no  dealings  with  him  in  the  way  of  fondling  and  caressing, 
so  customary  amongst  these  cebi,  especially  in  captivity.  It  is  pretty  much  the 
same  thing  that  occurs  in  the  relations  between  imbeciles  and  normal  beings,  leaving 
aside  the  sentiment  of  pity  in  the  normal  man,  a  sentiment  followed  by  that  of 
protection  and  guardianship,  or  the  utilitarian  sentiment,  when  the  imbecile  is 
capable  of  rendering  some  service,  as  often  happens,  provided  he  is  not  of  a  low 
grade. 

If  surprised  by  the  somewhat  strident  sound  of  the  bugle,  which  is  not  new  to 
them,  the  two  mutilated  monkeys  are  startled,  and  crouch  up  in  a  corner  of  the 
room  or  near  a  wall.  F,  on  the  other  hand,  after  the  first  impression  of  surprise, 
turns  on  me  and  my  instrument  a  gaze  that  is  half  curious,  half  interrogative,  then 
looks  hard  and  long  at  the  fearful  attitude  of  E  and  G  with  an  air  that  I  can  only 
describe  as  one  of  pity  for  those  two  unfortunates.  If  E  and  G  meet  one  another 
as  they  stroll  around  the  room,  each  on  his  or  her  own  account,  they  stop,  touch  one 
another  and  remain  for  a  little  while  near  each  other,  but  there  is  no  enthusiasm 
and  none  of  those  ardent  manifestations  of  sexuality  such  as  we  have  seen  in  normal 
couples.  There  is  an  occasional  but  futile  attempt  at  copulation  characterised  by 
brutality  and  stupidity.  The  attempt  is  abandoned  and  each  remains  quite  in- 
different towards  the  other.  It  is  noteworthy  that  F  manifests  no  enthusiasm  for 
the  now  stupid  G. 


Summing  up  briefly  the  main  points  in  the  psychology  of  monkeys  that 
have  suffered  mutilation  of  the  frontal  lobes,  the  following  results  may  be 
regarded  as  confirmed  : — 

1.  Defect  of  the  perceptive  power  consisting  in  an  incomplete  perception 
of  the  objects  of  the  external  world,  a  perception  which  is  lacking  in  certain 
of  the  specific  and  differential  features  and  accordingly  gives  rise  to  defective 
recognition  of  objects  already  known  and  of  new  objects  having  relations  of 
similarity,  analogy,  etc.,  with  those.  So  it  happens  that  some  objects  are 
mistaken  for  others  that  resemble  them  only  in  colour  or  in  form.  There  is 
also  a  notable  defect  in  the  perceptive  power,  in  the  sense  that,  whilst  intact 
animals  let  nothing  escape  them  and  are  constantly  poking  about  and  taking 
stock  of  anything  that  exists  in  any  particular  environment,  mutilated 
monkeys,  on  the  other  hand,  allow  a  number  of  things  and  situations  to  pass 
unobserved.  Further,  whilst  the  normal  cebus  distinguishes  the  reality  or 
pretence,  let  us  say,  of  a  threat,  from  the  attitude  of  the  experimenter,  the 


184  THE  MECHANISM  OF  THE  BRAIN 

mutilated  monkey  fails  completely  to  recognise  the  deception,  no  matter 
how  often  the  pretended  threat  is  repeated.  A  joke  falls  entirely  without  the 
perceptive  power  of  a  mutilated  monkey.  Perceptions  are  limited  to  the 
grosser  features  of  the  stronger  stimuli.  Everything  else  remains  outside 
the  perceptive  field. 

2.  Memory,  weak  and  unreliable,  becomes  enormously  reduced,  not  only 
for  recent  but  also  for  old  acquisitions.     The  mutilated  monkey  does  not 
utilise  past  experience ;    he  persists  always  in  repeating  the  same  actions, 
without  profiting  from  the  futility  of  the  previous  action,  and  without  making 
any  alteration  so  as  to  arrive  at  a  determined  object.    When  he  allows  himself 
to  be  tricked  many  times  in  succession,  as  he  is  made  to  take  a  finger  instead 
of  a  piece  of  sugar  or  fruit  with  which  he  has  been  enticed,  that  indicates 
that  he  does  not  remember  the  futility  of  his  actions,  and  does  not  notice  the 
ridiculous  position  in  which  he  places  himself,  although  normal  cebi  are  very 
susceptible  to  ridicule.    When  he  takes  a  cherry  embittered  with  quinine 
and  puts  it  in  his  mouth  without  suspicion,  although  the  same  experiment 
was  performed  the  previous  day,  this  would  indicate  that  there  is  an  immediate 
reflex  to  impressions,  without  the  intervention  of  memories  of  similar  or 
analogous  situations.     Mutilated  monkeys,  incapable  as  they  are  of  utilising 
all  their  experience,  have  consequently  lost  that  biophylactic  power  which 
serves  as  a  guide  through  life,  amongst  the  difficulties  interposed  by  the 
physical  environment  and  those  offered  by  fellow-beings  living  therein. 

3.  The  associative  power  is  greatly  reduced.     The  controlling  power  of 
practical  experience  and  acquisitions,  such  as  a  normal  monkey  exhibits  in 
the  varied  situations  of  its  existence,  especially  in  captivity,  which  offers 
opportunity  for  new  adaptations,  is  absent  or  withdrawn  from  the  mutilated 
monkey.     Judgment  is  poor  and  immediate,  often  erroneous,  owing  to  the 
absence  of  elements  of  contrast,  as  when  the  mutilated  monkey  stops  to 
pick  up  pieces  of  plaster,  or  straws  or  dry  leaves,  or  when  it  stops  in  front 
of  a  spot  on  the  wall,  which  it  persistently  touches  with  the  finger  (defect 
of  perception  and  of  association,  in  so  far  as  recognition  is  made  up  of 
associations) . 

What  is  more  important  is  the  fact  that  there  is  a  complete  absence  of 
any  initiative  in  those  animals  upon  which  the  operation  has  been  success- 
fully accomplished.  The  movements  performed  lack  any  evident  objective. 
They  are  the  effect  of  internal  impulses  which  readily  become  automatisms, 
or  they  are  reflexes  following  immediately  upon  simple  impressions,  which 
do  not  find  a  field  of  association  or  co-ordination,  so  as  to  achieve  a  deter- 
mined object.  The  monkey  which  used  to  jump  on  to  the  window-ledge; 
to  call  out  to  his  companions,  after  the  operation  jumps  on  to  the  ledge 
again,  but  does  not  call  out.  The  sight  of  the  window  determines  the  reflex 
of  the  jump,  but  the  purpose  is  now  lacking,  for  it  is  no  longer  represented 
in  the  focal  point  of  consciousness. 

Another  monkey  sees  the  handle  of  the  door  and  grasps  it,  but  the 
mental  process  stops  at  the  sight  of  the  bright  colour  of  the  handle  ;  the 
animal  does  not  attempt  to  turn  it  so  as  to  open  the  door,  but  sits  on  it. 


EXPERIMENTAL  HISTORIES  OF  DOGS,  FOXES  &  MONKEYS     185 

Evidently  there  are  lacking  all  those  other  images  that  are  necessary  for 
the  determination  of  a  series  of  movements  co-ordinated  towards  one  end. 
None  of  the  monkeys  operated  upon  has  shown  the  existence  of  that  regula- 
tive and  inhibitive  power  which  it  possessed  prior  to  the  operation.  Hiding 
under  a  couch  for  a  longer  or  shorter  period,  watching  for  the  occasion  which 
offers  an  opportune  moment  to  seize  the  fruit  lying  on  the  table  at  which 
someone  is  sitting,  is  based  on  association  and  detention  of  the  end  in  view 
in  the  focal  point  of  consciousness.  Jumping  on  to  the  table  and  first  of  all 
getting  possession  of  the  stick,  so  as  to  be  able  to  seize  the  fruit  with  impunity, 
is  the  expression  of  a  series  of  reasonings  calculated  to  achieve  the  end  in 
view  with  the  least  possible  risk. 

The  attitude  of  dignified  indifference  displayed  by  a  normal  monkey 
after  it  has  been  tricked  once  or  twice  is  the  result  of  reasonings  and  senti- 
ments based  on  memory  and  association,  of  which  the  mutilated  monkey  is 
totally  incapable.  The  self-restraint  exercised  by  a  normal  monkey  after 
being  cheated,  even  when  the  experimenter  offers  it  fruit  of  which  it  is  very 
fond,  contrasts  markedly  with  the  behaviour  of  the  mutilated  monkey,  which 
goes  through  the  same  movements  time  and  again,  perhaps  ten  or  twenty 
times,  in  order  to  obtain  a  piece  of  sugar  or  fruit — behaviour  which  reveals 
an  incapacity  to  utilise  past  experience.  In  the  latter  case  there  is  a  defect 
of  that  sentiment  of  self,  which  we  speak  of  as  dignity,  for  I  can  hardly  qualify 
it  otherwise  in  the  case  of  a  monkey  which,  though  hungry,  turns  its  head 
and  eyes  to  the  other  side  when  offered  something  which,  utilising  its  imagina- 
tion and  memory,  it  believes  to  represent  once  again  that  same  insidious 
deception  which  has  already  led  to  its  mortification.  Indeed,  the  normal 
monkey  exhibits  a  true  inhibition  that  is  almost  human  in  character.  Again, 
if  he  controls  that  instinctive  impulse  that  is  aroused  by  the  sight  of  eatables 
lying  within  his  reach — fruit,  let  us  say,  of  which  he  is  very  fond — and  calmly 
awaits  an  opportune  moment  to  snatch  it  from  the  hands  of  the  experimenter 
with  an  air  of  satisfaction,  that  surely  is  proof  not  only  of  inhibition  but  also 
of  premeditation  (imagination) .  No  doubt  one  can  hardly  claim  that  such  be- 
haviour is  the  outcome  of  a  logical  process  involving  a  series  of  notions,  such 
as  can  only  be  manifested  with  the  help  of  language,  yet  there  is  certainly 
a  logical  process  involved,  based  on  memories,  representations  and  imagina- 
tion, as  comprised  within  the  limited  circle  in  which  the  mental  life  of  the 
cebus  revolves. 

4.  Mutilation  of  the  frontal  lobes  gives  rise  to  a  no  less  remarkable  modi- 
fication in  the  emotional  and  sentimental  manifestations  of  the  life  of  these 
monkeys.  It  is  well  here  to  draw  a  distinction  between  the  primitive  emotions 
—  especially  that  irrational,  illogical  fear,  which  the  majority  of  the  mutilated 
monkeys  displayed — and  sentiments  or  emotions  of  a  higher  order.  The 
desire  for  satisfaction  of  hunger,  thirst,  and  other  organic  needs,  persists. 
The  obstinacy  displayed  by  a  mutilated  monkey  in  its  endeavours  to  open 
the  closed  fist  in  which,  a  moment  before,  it  caught  a  glimpse  of  a  piece  of 
sugar,  along  with  the  failure  to  adopt  a  change  in  method  after  repeated 
deceptions  practised  upon  it,  shows  the  intensity  of  the  desire.  The  fact  that 


186  THE  MECHANISM  OF  THE  BRAIN 

it  runs  after  eatables  shows  that  the  immediate  perception  of  food  material 
excites  desire  and  adequate  movements,  apart  from  the  slowness  of  these  in 
comparison  with  normal  monkeys  and  their  consequent  inferiority  in  com- 
petition with  healthy  companions.  The  defect  that  is  most  outstanding 
after  mutilation  of  the  frontal  lobes  consists  in  the  entire  absence  of  the 
higher  sentiments;  which  represent  a  complication  of  the  primitive  emotions 
with  numerous  new  factors.  The  sentiments  of  friendship,  gratitude, 
jealousy,  maternity,  protection,  dominion,  authority,  self-esteem,  ridicule 
and,  above  all,  that  of  sociality,  all  these  disappear  after  mutilation  of  the 
frontal  lobes,  whilst  the  primitive  emotions  remain,  sometimes  even  intensified, 
but  not  adapted  for  the  struggle  for  existence,  in  which  these  now  inferior 
animals  succumb.  In  a  later  chapter  we  shall  return  to  this  question  of  the 
emotions  and  sentiments. 

5.  In  all  cases  the  conduct  is  seen  to  be  incoherent.  This  incoherence  is 
due  to  defect  of  imagination  and  of  memory,  to  incapacity  to  represent  and 
sustain  an  objective  in  the  focal  point  of  consciousness.  The  incapacity  to 
support  the  objective  by  calling  up  the  requisite  correlative  images  (in 
obedience  to  the  hedonistic  law  which  governs  conduct) ,  in  order  to  formulate 
judgments  and  regulate  conduct,  explains  the  incoherence  of  these  mutilated 
animals.  The  whole  psychic  tone  is  lowered.  Torpor  and  stupidity  dominate 
the  scene. 

Attention  must  also  be  directed  to  the  stereotypes  and  tics.  The  history 
of  some  of  these  animals  provides  several  examples  of  tics  and  stereotypes, 
such  as  we  often  observe  in  dements  and  especially  in  imbeciles  and  idiots. 
We  know  that  tics  represent  a  phenomenon  of  degeneration,  in  as  much  as 
the  lower  centres  are  withdrawn  from  the  regulative  powers  and  the  discipline 
of  the  higher  centres.  The  fact  itself  that  these  phenomena  are  very  frequent 
in  imbeciles  and  idiots  indicates  a  close  analogy  in  their  origin,  in  respect 
that  they  evidently  depend  upon  an  insufficient  evolution  of  the  frontal  lobes 
in  the  case  of  imbeciles,  and  upon  destruction  of  the  frontal  organs  in  the 
animals  experimented  upon. 


CHAPTER  VI 

The  Excitable  Cortical  Area  of  the  Frontal  Lobe  and 

its  Significance 

THE  phenomena  provoked  by  electric  excitation  of  the  frontal  lobe  are  of 
very  obscure  origin  and  not  readily  explained. 

It  is  first  of  all  to  be  noted  that  between  the  motor  zone  (ascending 
frontal  convolution)  and  the  excitable  area  of  the  pre-Rolandic  lobe  there 
is  found,  in  monkeys,  a  thin,  irregular  strip  which  is  inexcitable  and  variable 
in  extent  in  individual  animals.  In  front  of  this  strip,  posterior  to  the 
pre-frontal  sulcus,  or  in  some  cases  at  the  anterior  margin  of  this  sulcus; 
there  is  an  area  which  is  excitable,  in  the  order  shortly  to  be  mentioned. 

Hitzig l  observed  combined  movements  of  the  head  and  eyes  on  exciting 
the  presigmoid  area  in  the  dog.  As  these  movements  were  combined,  he 
believed  that  he  was  warranted  in  inferring  that  they  were  not  the  effect 
of  particular  representations ;  that,  rather,  they  depended  upon  excitation 
of  organs  of  co-ordination.  Reasoning  from  analogy,  he  thought  that  there 
existed  on  the  cortex  of  the  brain  an  organ  for  isolated  movements  of  the 
eyes,  quite  as  independent  as  the  other  cortical  motor  centres. 

Ferrier  2  denned  more  clearly,  in  the  brain  of  the  monkey,  an  area  which 
comprises  the  neighbouring  halves  of  the  two  posterior  thirds  of  the  superior 
and.  middle  frontal  convolutions,  excitation  of  which  provokes  opening  of 
the  eyes,  dilatation  of  the  pupil,  and  deviation  of  the  head  and  eyes  to  the 
opposite  side.  Only  in  three  cases  did  he  succeed  in  provoking  isolated 
movements  of  the  ocular  bulbs  towards  the  opposite  side,  by  means  of  electric 
excitation  in  the  pre-frontal  region  (see  area  12,  Fig.  50). 

He  obtained  like  movements  of  the  eyes  to  the  opposite  side  by  exciting 
the  areas  marked  with  the  numbers  13  and  13'  (the  two  branches  of  the 
angular  gyrus) ,  with  this  difference,  that  the  movements  of  the  ocular  bulbs 
were  directed  upwards  on  exciting  area  number  13,  and  downwards  on 
exciting  13'. 

He  observed  that  there  generally  was  contraction  of  the  pupil  on  exciting 
these  areas  (13  and  13'),  just  as  when  the  eyes  are  subjected  to  the  influence 
of  light. 

Luciani  and  Tamburini 3  occasionally  observed  dilatation  instead  of 
contraction  of  the  pupil. 

Ferrier  attributed  little  importance  to  this  fact,  because  he  found  he  could 

1  Hitzig.      Untersuchungen  uber  das  Gehirn.     Berlin,  1904. 

2  Terrier.     The  Functions  of  the  Brain.     2nd  edit.       1886. 

3  Luciani  and  Tamburini.     "  Su  i  centri  psico-sensorii  corticali."     Riv.  sper.  di 
Fren.     1879. 

187 


188  THE  MECHANISM  OF  THE  BRAIN 

have  either  contraction  or  dilatation,  according  as  the  animal  experimented 
upon  was  in  a  state  of  sleep,  or  was  awake  and  had  its  eyes  open. 

Horsley  and  Schafer 1  defined  more  clearly,  on  the  frontal  lobe  of  the 
monkey,  an  area  situated  in  front  of  the  pre-frontal  sulcus,  excitation  of 
which  produced  deviation  of  the  eyes  and  head  to  the  opposite  side. 

Bechterew  2  succeeded  in  isolating,  in  monkeys,  an  area  of  the  frontal 
lobe,  excitation  of  which  provoked  isolated  movements  of  the  eyes  with 
deviation  of  the  head.  Further,3  he  found  a  particular  centre  for  divergence 
of  the  eyes,  on  the  foot  of  the  second  frontal  convolution  in  the  monkey. 
Excitation  at  this  point  produced  a  slight  elevation  of  the  upper  eyelid, 
dilatation  of  the  pupil  and  divergence  of  the  eyes.  He  states  that  as  long 
ago  as  1885-1886  he,  along  with  Mislawski,  had  succeeded  in  producing  a 
significant  dilatation  of  the  pupil  and  exophthalmos,  in  dogs,  by  exciting 
neighbouring  parts  of  the  anterior  and  posterior  branches  of  the  sigmoid 
gyrus  with  a  weak  faradic  current.  He  subsequently  obtained  similar  results 
in  the  monkey  by  exciting  the  posterior  tract  of  the  second  frontal  con- 
volution— i.e.  he  obtained  dilatation  of  the  pupil  associated  with  a  series 
of  other  movements  such  as  opening  of  the  eye  and  inward  movements  of  the 
third  eyelid,  precisely  as  observed  on  exciting  the  sympathetic  in  the  neck. 

Levinsohn4  has  observed  dilatation  of  the  pupil  following  excitation  of 
diverse  points  of  the  cerebral  mantle — the  occipital  region,  the  visual  sphere 
and  that  of  the  ocular  movements — but  he  denies  the  existence  of  any 
isolated  centre  for  dilatation  of  the  pupil. 

Pearson,6  in  many  of  his  researches  upon  dogs  and  cats,  obtained  dilatation 
of  the  pupil,  more  on  the  opposite,  but  also  on  the  homonymous,  side,  by 
exciting  either  the  occipital  lobe  or  the  frontal  region.  Section  of  the 
sympathetic  in  the  neck,  according  to  this  author,  weakens  but  does  not 
suppress  dilatation  of  the  pupil. 

The  areas  mentioned  and  illustrated  by  these  and  other  authors  do  not 
perfectly  correspond,  but  this  does  not  detract  from  the  value  of  the  fact 
itself,  which  remains  fairly  well  established. 

Stewart,6  in  the  last  edition  of  his  work,  locates  the  motor  centres  of  the 
eyes,  in  dogs,  on  the  anterior  part  of  the  second  external  convolution  which, 
curving  downwards  and  forwards,  embraces  and  surrounds  the  sigmoid 
gyrus.  The  present  writer 7  has  pointed  to  the  posterior  limit  of  this  zone 

1  Horsley  and  Schafer.     "  A  Record  of  Experiments  upon  the  Functions  of  the 
Cerebral  Cortex."     Phil.  Trans.     1888. 

2  Bechterew.      tJber    die    Ergebnisse    der    Untersuchungen    der    Erregbarkeit    des 
hintere  Abschnittes  des  Stirnlappens.     1889.     Loc.  cit. 

3  Bechterew.     Die  Functionen  der  Nervencentra.     Heft  3.     1911. 

4  Levinsohn.     "  tJber  die  Beziehungen  zwischen  Grosshirnrinde  und  Pupillen." 
Zeitschrift /.  Augenheilk.     1902. 

6  Pearson.  "  On  the  Dilatation  of  the  Pupil."  Collected  Papers  of  Physiolog. 
Laboratory.  1903. 

6  Stewart.     A  Manual  of  Physiology.     5th  edit. 

7  Bianchi.     "  Le  compensazioni  funzionali  del  mantello  cerebrale.     La  Psichia- 
Iria,  la  Neuropatologia,  etc.,  1883,  and  Riv.  sper.  di  Fren.     1882. 


THE  EXCITABLE  CORTICAL  AREA  OF  THE  FRONTAL  LOBE    189 

as  forming  a  part  of  the, visual  area  of  the  dog,  because  excitation  thereof 
produces  contraction  of  the  eyelids,  the  protective  organ  of  the  eye,  whilst 
destruction  of  the  same  area  produces  amblyopia  of  the  opposite  side. 
This  area  almost  coincides,  certainly  is  in  contact,  with  the  area  of  the  facial 
nerve.  The  area  for  dilatation  of  the  pupil  is  indicated  as  lying  on  the 
anterior  branch  of  the  sigmoid  gyrus,  near  the  cruciate  sulcus. 

In  the  chimpanzee's  brain,  Sherrington  and  Griinbaum  1  found  the  area 
for  the  eyes  situated  well  in  front,  on  the  external  surface  of  the  frontal  lobe 
and  separated  from  the  motor  zone  by  an  inexcitable  strip,  whilst  Horsley 
and  Beevor,2  experimenting  on  the  orang-outang,  found  the  area  of  excitation 
of  the  ocular  muscles  in  front  of  the  pre-frontal  sulcus,  almost  in  the  centre  of 
the  frontal  lobe. 

Schafer, 3  in  his.  classic  work  on  physiology,  shows  great  competence  in 
dealing  with  the  majority  of  those  questions  that  have  reference  to  the  nervous 
system,  but  he  dedicates  only  a  few  lines  to  the  effects  of  electric  excitation 
of  the  cortex  upon  the  pupil.  He  accepts  the  results  of  the  experiments  of 
Ferrier  and  others  and  states  that  weak  excitations  do  not  give  rise  to  altera- 
tion of  the  pupil  unless  they  fall  upon  regions  of  the  cortex  connected  with 
the  movements  of  the  head  and  eyes.  This  statement  does  not  altogether 
agree  with  the  results  of  the  investigations  described  by  the  present  writer 
and  others. 

There  are  two  regions  excitation  of  which  produces  movements  of  the 
head  and  eyes  accompanied  by  widening  of  the  palpebral  fissure  on  the 
opposite  side — viz.  the  area  just  indicated,  situated  in  front  of  the  motor 
zone,  and  another  area  well  known  as  the  visual  zone  and  situated  in  the 
occipital  lobe.  It  is  to  be  added  that  excitation  of  a  point  of  the  first  temporal 
convolution  which  may  provoke  movements  of  the  head  and  eyes  (when 
the  current  is  very  strong  (Bianchi))  also  produces  contraction  of  the  pupils. 

Conjugate  movements  of  the  eyes  to  one  side  and  upwards  or  downwards, 
along  with  deviation  of  the  head,  were  much  better  defined  by  Schafer  and 
Mott 4  as  depending  upon  differentiated  areas  of  the  zone  in  question.  Their 
experiments  were  carried  out  upon  a  species  of  cercopithecus,  the  brain  of 
which  seems  better  differentiated  than  that  of  the  macacus.  The  results 
obtained  by  excitation  were  more  marked  when  this  was  applied  to  the  area 
corresponding  to  the  angle  of  the  pre-frontal  sulcus.  Stimulation  of  the 
posterior  margin  of  this  area  produced  rotation  and  erection  or  retraction  of 
the  opposite  ear,  sometimes  also  of  the  ear  of  the  same  side. 

Sherrington5  holds  that  this  frontal  area  also  exercises  an  inhibitive 

1  Sherrington  and  Griinbaum.     "  Observations  on  the  Physiology  of  the  Cerebral 
Cortex  of  the  Anthropoid  Apes."     Proc.  Roy.  Soc.     Vol.  1. 

2  Horsley  and  Beevor.     "  A  Record  of  the  Results  obtained  by  Electric  Excitation 
of  the  So-called  Motor  Cortex  in  the  Orang  (Simia  Satyrus)."     Philos.  London. 
1890. 

3  Schafer.     Text-Book  of  Physiology.     1900. 

4  Schafer  and  Mott.     Brain.     1890. 

5  Sherrington.     "  Further  Researches  on  the  Movements   of  the    Eye."     The 
Journal  of  Physiology,  1894-1895. 


190  THE  MECHANISM  OF  THE  BRAIN 

action  on  the  antagonistic  ocular  muscles,  and  that  in  any  case  the  results 
obtained  are  not  to  be  attributed  either  to  the  corresponding  zone  of  the 
frontal  lobe  of  the  opposite  side  or  to  that  for  conjugate  movements  of  the 
head  and  eyes  situated  in  the  angular  gyrus,  in  the  occipital  lobe  and  in 
the  first  temporal  convolution. 

In  the  course  of  the  experiments  the  author  has  carried  out  at  different 
intervals  upon  the  frontal  lobe  of  monkeys  (cebus) ,  he  has  always  noted,  in 
front  of  the  excitable  area  for  the  limbs,  another  excitable  area  (almost 
parallel  with,  but  separated  from,  it  by  a  thin  strip  no  broader  than  a  few 

C.KA 

S.C.R 
CF.S 


s.P.R.F 


Fig.  56. — Brain  of  cebus 

SPRF.  Pre-frontal  sulcus.— CFS.  Superior  frontal  con  volution.— CRA.  Anterior  Rolandic  convolution.— 
SCR.  Rolandic  fissure.— SS.  Fissure  of  Sylvius.— TS.  Superior  temporal  convolution 

millimetres)  fairly  wide  above,  much  narrower  below,  the  excitable  points 
within  this  area  being  disposed  in  a  determined  order.  These  points 
have  not  always  corresponded  exactly  in  the  different  animals  experi- 
mented upon.  Differences  greater  or  less  in  degree  have  been  noted  and 
found  to  depend  upon  various  circumstances  some  of  which  have  been 
ascertained.1 

The  accompanying  figure  (same  as  Fig.  51,  page  134)  shows  the  disposition 
and  order  of  these  excitable  areas  and  is  based  upon  the  more  frequent 
results  of  experiments  upon  the  higher  cebidso,  taking  into  account  the  total 
sum  of  individual  differences. 

1 .  Lateral  movements  of  the  head ;    contraction  of  the  muscles  of  the 
neck  on  the  opposite  side  and  sometimes  of  the  trunk. 

2.  Conjugate  contraction  of  the  muscles  of  the  neck  and  of  the  eyes,  on 
the  opposite  side. 

3.  Deviation  of  the  eyes  alone,  along  with  dilatation  of  the  pupil. 

4-.  Dilatation  of  the  pupil  on  the  opposite  side  alone  and,  if  the  current 

1  L.  Bianchi.  "Sur  la  signification  de  1'aire  corticale  du  lobe  frontal." 
Archives  Italiennes  de  Biologic.  Tome  LXVI.,  fasc.  iii.  1916,  1917. 


THE  EXCITABLE  CORTICAL  AREA  OF  THE  FRONTAL  LOBE    191 

is  slightly  increased  in  strength,  dilatation  also  of  the  pupil  on  the  same  side, 
and  deviation  of  the  eyes  to  the  opposite  side. 

5.  Movements  of  the  ear  on  the  opposite  side  (stronger  currents  give 
movements  also  of  the  ear  of  the  same  side  but  much  less  pronounced). 

Destruction  of  this  area  does  not  produce  paralysis  of  the  external  ocular 
muscles  nor  does  it  suppress  the  reflexes  of  the  iris.  During  the  first  few 
days  after  operation  one  does  observe  conjugate  deviation  of  the  head  and 
eyes  towards  the  side  of  the  lesion,  but  if  the  destruction  is  not  very  extensive 
so  that  the  area  of  the  neck  and  trunk  is  spared,  this  symptom,  accompanied 
as  it  often  is  by  circus  movements,  lasts  only  a  few  hours,  or  at  most  a  day. 
It  is  only  bilateral  mutilation  of  the  frontal  lobes  that  produces  temporary 
limitation  of  the  movements  of  the  pupils  and  of  the  eyes.  This  limitation 
lasts  several  days  so  that  the  physiognomy  assumes  a  certain  aspect  of 
immobility,  the  glance  being  lifeless,  as  though  the  animal  were  staring  into 
space.  It  is  this  aspect,  perhaps,  which  suggested  the  view  expressed  by 
Ferrier. 

It  thus  seems  a  well-established  fact  that  electric  stimulation  of  certain 
points  of  the  cortex  of  the  frontal  lobe  can  produce  movements  of  the  eyes 
in  various  meridians  and,  separately,  dilatation  of  the  pupil.  The  dilatation 
of  the  pupil  may  be  combined  with  movements  of  the  eyes,  or,  on  the  other 
hand,  it  may  occur  independently  as  the  result  of  excitation  of  a  distinct 
area,  differentiated  from  that  for  movements  of  the  eyes. 

It  is  not  at  all  easy  to  interpret  the  fact,  now  well  confirmed,  that  there 
exist  frontal  areas  where  excitation  provokes  movements  of  the  eyes,  pupils 
and  ears,  analogous  and,  so  far  as  comparison  goes,  similar  in  every  respect 
to  the  movements  obtained  by  exciting  the  respective  sensory  areas  in  the 
occipital  lobe,  the  angular  gyrus  and  the  first  temporal  convolution.  It  is 
not  to  be  accounted  for  by  supposing  the  existence  of  circles  of  diffusion  of 
the  electric  stimulus,  because  even  a  slight  displacement  of  the  exciting 
electrode  is  sufficient  to  give  rise  to  different  results.  Further,  it  has  long 
been  proved  that  isolation  of  the  different  zones  of  excitation  by  means  of  a 
circular  incision  around  each  area  does  not  modify  the  result  of  the  experi- 
ment.1 It  is  also  noteworthy  that  Bechterew,  after  incising  deeply  the 
cerebral  hemisphere  in  front  of  the  visual  area  of  the  animal  experimented 
upon,  again  obtained  the  same  ocular  movements  and  dilatation  of  the 
pupil,  on  exciting  the  frontal  area. 

The  dilatation  of  the  pupil  is  not  to  be  attributed  to  the  sympathetic 
because  it  persists  after  section  of  the  sympathetic  in  the  neck,  after  section 
of  the  spinal  medulla  on  the  level  of  the  first  cervical  vertebrae,  and  even 
after  section  through  the  posterior  quadrigeminal  bodies.  No  more  is  it  a 
question  of  reflexes,  because  the  only  reflex  which  can  reasonably  be  invoked 
would  be  that  associated  with  pain  due  to  stimulation  of  the  meningeal 
branches  of  the  trigeminal  nerve.  The  reflex  hypothesis,  however,  might 
acquire  a  certain  degree  of  probability  in  any  experiments  in  which  very 

1  Bianchi.  "  Sul  significato  della  eccitazioue  della  corteccia  cerebrale."  11 
Movimento  Med.  Chir.  Naples,  1881. 


192  THE  MECHANISM  OF  THE  BKAIN 

strong  currents  were  employed.  In  this  case  the  law  formulated  by  Franck 
and  Pitres  would  come  into  play — i.e.  that  all  currents  that  are  strong 
enough  to  invoke  epileptic  attacks,  no  matter  to  what  part  of  the  cerebral 
mantle  they  are  applied,  give  rise  at  the  same  time  to  dilatation  of  the  pupil. 

Our  experiments  on  the  other  hand  show  that  the  current,  when  of  com- 
paratively slight  intensity,  not  only  does  not  provoke  epileptic  convulsions 
but  does  not  give  rise  to  dilatation  of  the  pupil,  unless  the  two  electrodes 
fall  on  a  determined  small  area,  whilst  electric  excitation  above  this  area 
induces  movements  of  the  ocular  bulbs,  and,  below  the  said  area,  movements 
of  the  ear.  Further,  the  same  current,  applied  farther  back,  on  the  pre- 
central  gyrus,  produces  determined  movements  of  the  upper  limb  whilst, 
if  applied  farther  forward,  on  the  pre-frontal  area,  properly  so  called,  it 
produces  no  results. 

It  might  be  argued  that  what  we  have  to  deal  with  here  is  the  reawakening 
and  representation  of  visual  images  projected  into  space,  a  sort  of  hallucina- 
tion provoked  by  electric  stimulation  of  that  area.  This  hypothesis,  probable 
as  it  is,  so  far  as  the  interpretation  of  the  like  symptoms  produced  by 
electric  excitation  of  the  angular  gyrus  and  occipital  lobe  in  monkeys  is 
concerned,  cannot  be  applied  to  the  frontal  lobe  because  we  should  then  be 
obliged  to  admit  the  existence  of  a  second  area  of  formation,  conservation 
and  reproduction  of  visual  images,  and  this,  surely,  is  markedly  in  opposi- 
tion to  all  that  we  know  to-day  of  the  sensory  areas.  The  two  following 
considerations  should  be  sufficient  to  dispose  of  such  a  theory  : — 

1.  The  area  of  excitation  for  dilatation  of  the  pupil  is  very  limited. 
Those  authorities  who,  in  their  respective  publications,  have  indicated  a 
much  larger  area  on  the  frontal  lobe  have  certainly  employed  currents  that 
were  too  strong. 

2.  It  is  difficult  to  understand  the  bis  in  idem.    We  should  have  to  admit 
the  same  thing  in  the  case  of  the  auditory  area,  since  electric  excitation  in 
the  frontal  area  produces  movements  of  the  ear  that  do  not  differ  from  those 
provoked  by  electric  excitation  of  the  first  temporal  convolution,  and  there 
is  no  reasonable  explanation  for  such  miniature  replicas  of  the  sensory  areas 
in  the  frontal  lobe.     The  fact  remains  that,  in  all  cases,  destruction  of  the 
frontal  lobe,  including  the  area  for  movements  of  the  pupils  and  the  ear, 
has  never  produced  paresis  of  the  motor  apparatus  of  the  respective  senses, 
nor  permanent  defect  of  perception  or  of  recognition.     No  doubt  it  is  true 
that  after  removal  of  the  frontal  lobes  in  the  monkey  and  in  the  dog  one 
does  observe  visual  disorders  very  similar  to  those  that  follow  destruction 
of  the  occipital  lobe.     These  signs,  however,  are  often  fleeting  in  character, 
disappearing  in  the  course  of  a  few  weeks,  so  that  often  there  remains  no 
perceptive  deficit  in  the  animals  operated  upon.     The  theory  in  question 
does  not  withstand  criticism. 

Bechterew l  is  inclined  to  the  view  that  the  dilatation  of  the  pupil  is 
the  concomitant  of  an  effort  at  accommodation,  coinciding  with  phenomena 
dependent  upon  the  sympathetic. 

1  Bechterew.     LOG.  cit. 


THE  EXCITABLE  CORTICAL  AREA  OF  THE  FRONTAL  LOBE    193 

Griinhagen  and  Bessau  found  that,  even  after  section  of  the  sympathetic 
in  the  neck,  excitation  of  certain  points  of  the  cortex  still  gives  rise  to  dilata- 
tion of  the  pupil.  Although  the  signs,  provoked  by  cortical  excitation, 
resemble  those  due  to  excitation  of  the  sympathetic  in  the  neck  (dilatation 
of  the  pupil,  exophthalmos  and  adduction  of  the  third  eyelid),  one  cannot 
deny  the  dilating  action  of  the  cortex  upon  the  pupil,  independently  of  that 
of  the  sympathetic  in  the  neck. 

On  the  other  hand,  Braunstein  l  has  maintained  that  dilatation  of  the 
pupil  might  result  solely  from  an  inhibitive  action  of  the  cortical  excitation 
upon  the  nuclei  of  the  ocular  motor  nerve. 

The  present  writer  advances  the  hypothesis  that  the  movements  of  the 
eyes,  pupil  and  ear  (possibly  there  will  yet  be  discovered  others  connected 
with  the  senses  of  smell  and  taste,  senses  that  are  certainly  less  intellectual 
and  more  inherent  in  the  instincts,  and  accordingly  not  so  well  represented 
in  the  frontal  lobe)  represent  motor  organs  that  are  closely  bound  up  with 
another  order  of  psychic  processes  of  a  more  elevated  character,  coinciding 
with  the  mechanism  of  attention. 

One  need  not  here  enlarge  upon  the  findings  of  psychologists,  who, 
pursuing  their  inquiries  along  another  path,  are  often  led  to  draw  a  dis- 
tinction between  sensory  perception  that  is  immediate  and  involuntary 
and  voluntary  perception  associated  with  the  mechanism  of  attention  (the 
apperception  of  Wundt).  In  involuntary  sensory  perception  the  move- 
ment of  the  head  and  eyes,  or  of  the  eyes  alone,  as  well  as  the  movements 
of  the  pupils  and  eyes,  are  true  reflexes,  or  movements  of  perceptive  adapta- 
tion, that  follow  immediately  upon  the  modification  induced  by  the  stimulus, 
which  reaches  its  appropriate  cortical  field  by  its  ordinary  centripetal  paths. 
In  voluntary  perception,  on  the  other  hand,  a  much  more  complicated 
mechanism  is  brought  into  play.  In  this  the  more  important  elements  are  : 
interest  in  the  examination  of  something  which  is  present  or  preperception 
of  something  which  is  expected,  fixation  or  immobilisation  of  the  object  of 
perception  or  preperception  in  the  focal  point,  re- evocation  of  the  images 
(image-records)  bound  up  with  the  object  of  perception  in  so  far  as  it  reflects 
past  experience,  curiosity,  preoccupation  based  upon  past  experience,  etc. 
When  one  watches  the  movements  of  a  pointer  dog  as  he  steps  carefully  and 
.circumspectly  a  short  distance  in  front  of  the  sportsman,  as  he  keenly  follows 
up  the  traces  of  the  prey  whose  tracks  he  has  now  noticed,  and  sees  him  come 
to  a  dead  stop,  gazing  intently  at  the  game  as  soon  as  he  has  caught  a  glimpse 
of  it  lying  hidden  in  the  broken  ground  or  under  thick  cover,  one  must  be 
convinced  that  herein  there  is  involved  a  much  more  complex  mechanism 
than  the  mere  erection  of  the  ears  and  the  raising  and  turning  of  the  head 
and  eyes  towards  any  point  from  which  has  come  a  noise  that  has  broken 
in  upon  his  repose.  The  careful  curiosity  which  a  monkey  displays  towards 
anything  new  falling  under  his  senses,  the  minute  examination  he  makes  of 
persons,  objects  and  food  stuffs,  the  study  he  gives  to  the  overcoming  of  new 

1  Braunstein.     Zur  Lehre  von  der  Innovation  der  Pupillenbewegungen.     Charkow, 
1895. 


194  THE  MECHANISM  OF  THE  BRAIN 

difficulties,  along  with  the  keen,  mobile,  intent  glance,  full  of  craft,  suspicion 
and  desire,  promoted  by  preperception  and  accompanied  by  a  surprising 
mobility  of  the  pupil,  are  facts  that  are  closely  and  inseparably  bound  up 
with  one  another. 

In  all  this  one  cannot  pretend  to  see  merely  a  simple  reflex.  Rather  are 
we  dealing  with  an  attentive  perception,  with  preperception,  with  new, 
combined  with  past,  experience,  with  the  evocation  of  memories,  and  the 
representation  of  similar  or  analogous  images.  To  my  thinking,  pupillary 
movements  are  inseparable  from  such  a  complex  of  emotions,  representations, 
experiences  and  will.  Just  as  certain  organic  phenomena  are  intimately 
bound  up  with  a  particular  representation  in  the  emotions  of  pleasure  and  of 
pain,  just  as  in  the  minds  of  some  physiologists  emotion  cannot  be  conceived 
as  separate  or  separable  from  organic  phenomena,  so  the  writer  believes  that 
the  mental  processes  cannot  be  separated  from  certain  motor  concomitants 
emanating  from  that  part  of  the  cerebral  mantle  which  is  approximate  to 
the  field  that  is  more  specifically  active. 

Of  course,  they  are  not  the  same  things.  Just  as  the  subjective  fact  of 
fear  and  the  content  of  fearful  images  or  precepts  are  not  the  same  as  the 
tremor,  the  vascular  constriction,  the  secretion  of  urine,  etc.,  which  are 
organic  phenomena  inseparable  from  the  emotion  of  fear,  so  pupillary  move- 
ments first  of  all,  and  next  ocular  movements,  are  strictly  bound  up  with 
the  movements  of  thought  as  it  ranges  through  the  infinite  tracts  from  which 
observation  and  imagination  draw  their  immense  constructive  material. 

Certain  experiments  upon  men  would  seem  to  confirm  the  existence  of  a 
frontal  centre  for  dilatation  of  the  pupil.  The  writer  need  only  mention  the 
experiments  of  Haab,1  Pilcz,2  Bunke  3  and  Bechterew,4  who  attempt  to 
establish  mental  reflexes  of  the  pupil  in  relation  with  voluntary  attention, 
and  even  claim  to  have  observed  voluntary  dilatation  of  the  pupil  in  some 
cases  (Bechterew). 

For  several  years  past  the  writer  has  been  carrying  out  observations 
which  seem  to  demonstrate  the  association  of  dilatation  of  the  pupil  with 
certain  voluntary  movements  involving  the  facial  nerve.  The  person 
observed  is  made  to  stand  facing  the  light.  The  observer,  with  his  fingers, 
lowers  the  eyelids  and  then  raises  them  separately  or  together.  The  result 
is  the  well-known  reflex  of  constriction  of  the  pupil,  less  marked  when  only 
one,  more  marked  when  both  eyelids  are  raised.  It  is  simply  a  method  of 
reproducing  the  classic  reflex  to  light.  If,  instead  of  bringing  down  the  eye- 
lids with  his  fingers,  the  observer  asks  the  subject,  still  in  the  same  position, 
to  shut  his  eyes  voluntarily  and  to  keep  the  eyelids  tightly  and  forcibly 
closed  and  then  to  open  them  quickly  and  forcibly  upon  a  given  signal, 
the  observer  can  detect,  in  the  act  of  opening,  a  marked  dilatation  of  the 

1  Haab.     "  Der  Hirnrindenreflex  der  Pupille."     Arch.  f.  Augenheilk.     1902. 

2  Pilcz.     "  Uber     Ausmerlsamkeitsreflexe     der     Pupillen."     Neural.      Central^. 
1899. 

8  Bunke.     Cited  by  Bechterew, 
4  Bechterew,     Loc.  cit. 


THE  EXCITABLE  CORTICAL  AREA  OF  THE  FRONTAL  LOBE  195 

pupils  which  rapidly  contract  again  to  light,  but  re -dilate  immediately  after- 
wards so  as  to  regain  the  medium  diameter  which  they  usually  have  with 
that  same  degree  of  illumination.  The  dilatation  of  the  pupil  which  follows 
protection  from  light  is  not  so  great  as  that  obtained  by  voluntary  and 
strong  closure  of  the  eyelids  or  by  rapid  and  forced  opening  of  the  eye,  this 
being  followed  immediately  by  contraction,  due  to  the  action  of  the  light 
(reflex).1 

Only  in  a  few  individuals  does  forcible  and  voluntary  closure  of  the  eyelids 
produce  contraction  of  the  pupil  but  in  any  case  what  we  have  here  to  deal 
with  are  voluntary  movements  of  the  pupil  associated  with  voluntary 
movements  of  the  orbicularis  palpebrarum. 

Another  simple  experiment  may  here  be  mentioned.  The  subject  is 
made  to  face  the  light  as  in  the  previous  experiment  and  the  observer  stands 
in  front  of  him  with  his  back  to  the  light.  The  subject  is  then  told  to  look 
at  a  small  object  placed  at  a  distance  of  30-40  centimetres  so  as  to  fix  the 
diameter  of  the  pupil.  The  observer  next  asks  him  to  think  of  his  distant 
home,  still  keeping  his  gaze  fixed  upon  the  object.  The  pupils  dilate  slightly. 
There  can  be  no  doubt  that  these  movements  of  dilatation  and  contraction 
of  the  pupil  are  bound  up  with  mental  processes  such  as  attention,  imagina- 
tion and  evocation.  Naturally,  the  experimental  results  are  more  marked 
in  those  subjects  who  are  more  intelligent,  more  willing,  more  deferent  to 
the  investigator,  who  have  at  the  same  time  a  more  lively  and  ready 
imagination.  Sometimes  a  certain  training  is  necessary.  Individuals  with 
light-coloured  are  more  sensitive  than  those  with  very  dark  irises. 


VISUAL  DISTURBANCES  IN  DOGS  AND  MONKEYS  AFTER  MUTILATION  OF  THE 

FRONTAL  LOBES 

As  may  be  inferred  from  the  preceding  experiments,  one  of  the  symptoms 
most  frequently  observed  as  the  result  of  extirpation  of  the  frontal  lobe 
consists  in  disturbance  of  vision,  in  the  form  of  amblyopia  of  the  opposite 
eye,  or  bilateral  hemiopia,  the  latter  condition  being  more  frequent.  As 

1  Dr  A  Westphaal  ("  tlber  ein  bischer  nicht  beschriebenes  Pupillen  Phanomen." 
Neur.  Centralb.  1899)  states  that  with  energetic  contraction  of  the  orbicularis 
palpebrarum  we  get  contraction  ( Verengerung)  of  the  pupil  of  the  corresponding  eye. 
The  same  phenomenon  (contraction  of  the  pupil  on  strong  closure  of  the  eyelids  and 
dilatation  on  reopening)  has  been  observed  by  Pierre  Marie  (La  Pratique  Neuro- 
logique)  in  41  per  cent,  of  tabetics.  I  have  carried  out  these  experiments  in  a  great 
number  of  healthy,  or  at  most  neurasthenic,  men,  and  in  a  high  percentage  have 
obtained  precisely  the  opposite  result,  as  already  described.  In  recent  times,  when 
examining  tabetics,  I  have  found  that  we  do  not  get  inversion  of  the  physiological 
fact  but,  rather,  a  state  of  pupillary  torpor.  It  is  certain  that  when  both  eyelids 
are  closed  tightly  we  almost  always  get  a  marked  dilatation  of  the  pupil  on  the 
reopening  of  the  eyelids,  a  dilatation  which  is  immediately  followed  by  contraction, 
and  then,  soon  afterwards,  by  moderate  re -dilatation.  It  is  found  that  voluntary 
and  forcible  action  of  the  orbicularis  of  both  eyelids  coincides  with  a  stronger 
dilatation  of  the  pupils. 


196  THE  MECHANISM  OF  THE  BRAIN 

to  the  actual  existence  of  this  symptom  there  is  no  room  for  doubt.  The 
debate  between  Hitzig,  who  vigorously  upheld  the  existence  of  visual  dis- 
turbance after  mutilation,  and  Munk,  who  denied  it  with  equal  obstinacy, 
was  settled  by  subsequent  observations  in  favour  of  the  existence  of  this 
symptom,  a  view  which  is  supported  by  the  cases  previously  referred  to. 
It  is,  however,  a  relatively  fleeting  symptom,  being  rarely  prolonged  beyond 
three  weeks.  It  has  been  found  in  both  dogs  and  monkeys.  The  method 
of  investigation  preferred  by  the  writer  consisted  in  the  application  of  a  sub- 
palpebral  eye-shade  of  caoutchouc.  This  caused  no  annoyance  and  it  allowed 
of  greater  certainty  in  ascertaining  the  results  of  the  experiments  ;  not  only 
so,  but  it  entirely  removed  any  doubt  as  to  the  actual  existence  of  the  symptom. 
Closing  the  eye  of  the  animal  to  be  examined  by  the  application  of  a  plaster 
or  small  forceps  to  the  eyelids,  or  by  bandaging,  causes  so  much  annoyance 
to  the  animal  that  it  becomes  restless  and  excited  and  attempts  in  every 
possible  way  to  free  itself  from  the  encumbrance.  The  method  employed  by 
the  writer  is  much  to  be  preferred  because  it  permits  the  animal  to  remain 
quiet  and  also  saves  time. 

If,  however,  the  existence  of  the  symptom  is  assured,  its  interpretation 
is  still  a  matter  of  some  doubt.  We  can  set  aside  the  theory  of  peripheral 
blindness,  for  the  simple  reason  that  in  most  cases  we  have  to  deal  with 
bilateral  homonymous  hemianopsia  (both  in  the  monkey  and  in  the  dog). 
I  merely  mention  this  theory  because  Hitzig  supported  the  view  that  "  the 
commencement  of  all  vision  consists  in  the  prompt  production  of  the  optic 
image  in  the  retina.  The  maintenance  of  vision  consists  in  the  combination 
of  these  images  with  the  motor  facts  and  perhaps  with  another  impression 
in  the  infracortical  centres."  l 

How  little  importance  is  to  be  attached  to  this  view  can  be  seen  from  all 
that  appears  in  the  first  chapter  of  this  book.  It  is  not  the  retinal  image 
which  is  transmitted  but  the  nervous  waves  into  which  the  luminous  waves 
are  transformed,  and  these  in  turn  reproduce  the  luminous  image.  As  for 
the  formation  of  the  concrete  image,  this  results  from  the  combination  of 
various  more  elementary  components.  That  the  cortical  visual  field  comes 
into  play  can  be  argued  from  the  fact  that  the  hemiopia  is  quite  similar 
to  that  which  results  from  excision  of  the  occipital  lobe. 

A  peculiar  thing  is  that  the  phenomenon  is  more  characteristic  when  only 
one  frontal  lobe  is  excised.  Observations  upon  monkeys  mutilated  in  both 
frontal  lobes  show  clearly  that  the  mutilated  animal  sees,  often  avoids 
obstacles,  and  picks  up  eatables.  The  only  remark  to  be  made  here  is  that 
if  some  solid  piece  of  food,  like  an  apple  or  chestnut,  is  thrown  at  some 
distance  from  it,  the  animal  runs  after  it  for  a  certain  distance  and  then  stops, 
either  as  the  result  of  deficient  attention  or  because  it  loses  sight  of  the 
object  owing  to  defect  of  the  attentive  accommodation. 

I  put  forward  the  hypothesis  that  the  bilateral  homonymous  hemianopsia 
is  a  phenomenon  of  diaschisis.  The  anatomical  and  functional  relations 

1  Hitzig.      "  Alte    und    neue    Untersuchungen    iiber    das    Gehirn."      Arch   fur. 
Psichiatrie.     Bd.  XXXVII.  ii.  2,  3. 


THE  EXCITABLE  CORTICAL  AREA  OF  THE  FRONTAL  LOBE   197 

between  the  occipital  and  frontal  lobe  are  fairly  well  marked.    Attentive 
vision,  which  gives  rise  to  a  kind  of  visual  apperception  in  the  dog  and  in 
the  monkey,  is  a  symptom  which  strikes  the  eye  of  any  observer.     The 
frontal  and  occipital  lobes  normally  function  in  concert.     The  anatomical 
relations  between  the  frontal  lobe  and  the  occipital  lobe  of  the  same  side  are, 
as  we  shall  see,  numerous,  and  one  can  therefore  readily  understand  why 
it  is  that  a  violent  lesion  of  the  frontal  lobe  of  one  side  brings  about  functional 
interdiction  of  the  occipital  lobe  of  the  same  side,  with  the  same  symptoms 
as  are  observed  after  removal  of  the  occipital  lobe.     Vision  becomes  gradually 
restored  in  the  mutilated  animals  and,  after  a  few  weeks,  all  sign  of  visual 
disturbance    has    disappeared.    When,    however,    both   frontal   lobes   are 
removed  the  glance  of  the  animal  never  again  acquires  that  vivacity,  that 
malicious,  crafty  and  suspicious  mobility  which  is  so  characteristic  of  the 
monkey.     Those  who  are  familiar  with  asylum  inmates,  gross  imbeciles  and 
young  dements,  will  more  readily  appreciate  the  resemblance  between  the 
looks  and  attitudes  of  such  patients  and  those  of  mutilated  monkeys.    Any- 
one who  compares  the  physiognomy  and  appearance  of  a  young  girl,  before 
the  onset  of  an  illness  which  has  left  her  demented,  with  her  general  appear- 
ance and  attitude  and  her  lifeless  and  vacant  glance  after  the  dementia  has 
impressed  itself  upon  her,  cannot  help  being  struck  by  the  marked  analogy 
between  the  two  states  in  the  two  diverse  conditions  of  existence.     That 
this  is  due  not  only  to  interdicted  movement  of  images,  to  suppressed  power 
of  evocation,  to  loss  of  interest  owing  to  defect  of  association,  but  also  to 
diminished  capacity  of  attention,  that  complex  movement  of  the  eyes  and 
pupils  so  intimately  connected  therewith,  seems  to  the  writer  to  permit  of 
no  doubt.     The  destruction  of  the  frontal  cortical  centres  for  those  move- 
ments of  the  eyes  and  pupils  which  are  so  strictly  bound  up  with  perception, 
evocation,  judgments  and  the  relative  emotional  states,  suppresses  the  organic 
basis  of  those  phenomena.    As  already  mentioned,  the  ocular  and  pupillary 
movements  represented  in  the  frontal  lobe  stand  in  the  same  relationship  to 
apperception  as  vascular  constriction  and  trembling  to  fear.    We  infer  the 
severe  mental  deficit  from  the  careless  and  indifferent  attitude  of  the  monkey 
and  from  the  wan,  expressionless  look,  void  of  that  vital  spark  which  we 
observe  in  intelligent  dogs  and  in  normal  monkeys,  whose  psychology  is  still 
far  from  being  completely  reconstructed.     Over  these  attitudes  we  have 
presiding  the  function  of  the  frontal  lobe  with  its  own  immediate  centres 
which  are  the  motor  organs  of  its  summarising  function,  located  in  definite 
order  one  above  the  other  on  the  frontal  zone,  these  conferring  upon  the 
higher  intellectual  processes  that  motor  expression  that  is  evidenced  by 
mobility  of  the  glance,  the  pupil  and  the  head. 


CHAPTER  VII 

Associative  Paths  between  the  Frontal  Lobe  and  the 
Sensory  Area  of  the  Cortex 

THERE  are  to  be  found  in  the  frontal  lobe  long  bundles  of  association  fibres 
which  connect  it  with  neighbouring  and  remote  cortical  areas  of  the  brain, 
and  short  paths  connecting  different  parts  of  the  frontal  lobe  itself.  The 
relations  between  the  frontal  region  and  the  motor  zone  are  especially  very 
numerous. 

The  intra-frontal  associative  bundles  are  not  so  distinct  as  those  in  the 
occipital  lobe  (vide  Chapter  I.)  but  at  the  same  time  are  capable  of  being 
traced.  Brief  mention  may  here  be  made  of  the  fibres  which  run  from  the 
internal  aspect  of  the  frontal  lobe  to  the  orbital  aspect  and  also  to  the  external 
surface ;  the  bundles  of  fibres  which  secure  reciprocal  communications  between 
the  orbital  convolutions  ;  other  fibres  running  from  the  superior  and  external 
surface  in  an  oblique  but  almost  vertical  direction  to  connect  the  respective 
convolutions  with  the  internal  surface ;  others,  again,  proceeding  from  the 
anterior  perforated  substance  to  distribute  themselves  in  the  orbital  portions 
of  the  first  and  third  convolutions.  It  is  unnecessary  here  to  dwell  at  length 
upon  these  connections. 

The  relations  of  the  frontal  lobe  with  the  other  parts  of  the  cerebral 
mantle  have  been,  in  the  main,  confirmed  by  all  anatomists  and  neurologists. 

Van  Gehuchten  l  gives  a  brief  description,  along  with  a  clear  figure,  of 
three  single  bundles  which  would  connect  the  frontal  lobe  with  the  other 
cortical  areas : — 

1.  The  superior  longitudinal  bundle  formed  of  fibres  which  unite  the 
grey  substance  of  the  frontal  lobe  with  that  of  the  occipital  and  temporal 
lobes. 

2.  The  cingulum  formed  of  fibres  running  antero-posteriorly  and  following 
the  direction  of  the  convolution  of  the  corpus  callosum,  joining  the  frontal 
with  the  temporal  lobe. 

3.  The  uncinate  or  unciform  bundle  which  unites  the  inferior  frontal 
convolution  (grey  substance)  with  the  tip  of  the  temporal  lobe. 

Dejerine  2  describes  four  association-bundles  composed  of  long  fibres : 
(a)  The  cingulum  is  considered  as  an  association-bundle  of  the  rhinen- 
cephalon.  It  follows  the  curve  of  the  limbic  lobe  and  composes  the  great 
mass  of  its  white  substance  (first  and  second  limbic  convolutions).  In  its 
course  it  exchanges  numerous  fibres  with  the  superior  frontal  convolution, 
the  parietal  lobule,  the  precuneus,  the  cuneus,  the  lingual  lobule,  the  fusiform 

1  Van  Gehuchten.     Systeme  nerveux  de  Vhomme.     Louvain,  1906. 

2  Dejerine.     Anatomie  des  centres  nerveux.     Paris,  1895. 

198 


ASSOCIATIVE  PATHS  BETWEEN  FRONTAL  LOBE  &  CORTEX   199 

lobule  and  the  temporal  pole.  It  is  generally  admitted  that  this  bundle 
establishes  relations  between  the  frontal  lobe  and  anterior  rhinencephalon  on 
the  one  hand  (Van  Gehuchten,  Dejerine,  Beevor)  and  the  median  part  of  the 
limbic  convolution,  perhaps  also  the  hippocampus,  besides  the  lingual  and 
fusiform  lobules  on  the  other  hand. 

According  to  Monakow  1  the  cingulum  contains  fibres  of  different  lengths. 
The  short  fibres  establish  relations  between  neighbouring  cortical  fields, 
whilst  the  long  fibres  connect  the  frontal  lobe  with  the  occipital  and  temporal 
lobes. 

(b)  The  uncinate  bundle  is  composed  of  relatively  short  fibres  which 
unite  the  temporal  pole  with  the  orbital  face  of  the  frontal  lobe,  passing 
underneath  and  behind  the  insula  in  its  anterior  segment. 

The  deeper  and  more  anterior  fibres  of  this  bundle  reach  the  third  frontal 
convolution  and  the  orbital  part  of  the  other  two  frontal  convolutions. 

(c)  The  superior  longitudinal  or  arcuate  bundle  runs  to  the  outside  of  the 
corona  radiata  (whilst  the  cingulum  runs  to  the  inside),  corresponding  to  the 
operculum  of  the  Sylvian  fissure.     In  vertico- transverse  sections  one  can 
readily  observe  that  this  bundle  describes  a  very  open  curve  downwards. 
The  more  superficial  and  inferior  fibres  pass  close  by  the  putamen  to  enter 
into  the  claustrum,  whilst  others  contribute  to  the. formation  of  the  antero- 
superior  part  of  the  internal  capsule  (?).     Its  fibres  spread  themselves  out 
into  the  anterior  and  posterior  parts  of  the  first  and  second  temporal  con- 
volutions, the  supra-marginal  gyms,  the  angular  gyrus  and  the  external 
surface  of  the  occipital  lobe.     This  bundle  derives  its  origin  from  the  whole 
convexity  of  the  frontal  lobe.* 

(d)  The  occipito-frontal  bundle.     This  bundle  was  identified  by  Forel 
and   Onufrowicz   with   the   arcuate   or  superior  longitudinal   bundle,  just 
described.    Dejerine  looks  upon  it  as  a  distinct  bundle  situated  to  the  inside 
of  the  corona  radiata.     It  runs  somewhat  above  and  a  little  to  the  outside  of 
the  caudate  nucleus  and  is  separated  from  the  lateral  ventricle  by  means 
of  the  sub-ependymal  grey  substance.     The  fibres  composing  it  come  from 
the  white  substance  of  the  frontal  lobe.     From  the  upper  and  outer  border 
of  the  caudate  nucleus,  where  they  become  collected  in  a  bundle,  they  proceed 
to  pass  between  the  caudate  nucleus  and  the  upper  border  of  th.e  putamen. 

This  bundle,  according  to  Dejerine,  describes  an  open  curve  forwards  and 
downwards,  is  well  defined  at  the  level  of  the  head  and  trunk  of  the  caudate 
nucleus,  curves  downwards  at  a  point  corresponding  to  the  ventricular 
carrefour  and  spreads  out  in  fanlike  fashion  to  form  the  tapetum.  Dejerine 
thinks  it  not  improbable  that  some  of  the  fibres  of  this  bundle  may  penetrate 
the  sub-ependymal  grey  substance. 

1  Monakow.     Gehirnkrankheiten.     1905. 

*  According  to  Schnopfhagen  the  fibres  of  the  arcuate  bundle  take  origin  in  the 
frontal  lobe  of  the  opposite  side,  and  would  reach  the  position  described  after 
crossing  through  the  corpus  callosum.  They  would  thus  serve  as  a  path  of  associa- 
tion of  the  frontal  lobe  of  one  hemisphere  with  the  temporal  and  occipital  lobes  of 
the  opposite  hemisphere.  This  view  has  not  been  confirmed. 


200  THE  MECHANISM  OF  THE  BRAIN 

The  fibres  composing  the  bundle  in  question  derive  their  origin  from  all 
the  cortex  of  the  frontal  lobe,  not  excluding  the  orbital  surface.  They 
intersect  at  various  angles  with  the  fibres  of  the  corpus  callosum  and  also 
with  those  of  the  corona  radiata,  and,  after  having  formed  the  tapetum, 
they  spread  themselves  out  in  the  grey  substance  of  the  convolutions  of  the 
occipital  and  temporal  lobes. 

This  bundle  (and  the  same  applies  to  the  other  great  association  paths, 
the  cingulum  and  the  arcuate  bundle)  is  not  composed  solely  of  fibres  running 
from  the  frontal  lobe  to  the  occipito- temporal  cortex.  It  also  contains  fibres 
which  come  from  the  occipital  and  temporal  lobes  to  the  frontal  lobe.  Lesions 
both  of  the  occipital  and  of  the  temporal  lobes  produce  degeneration  of  the 
occipito-frontal  and  temporo-frontal  fibres. 

Muratow  and  Monakow,  on  the  other  hand,  assert  that  the  fronto-occipital 
bundle  exhibits  partial  degeneration,  in  the  dog,  after  extirpation  of  the 
motor  zone  and  also  after  removal  of  the  occipital  and  temporal  lobes. 
These  findings  were  confirmed,  as  will  be  shown,  by  the  writer's  observations, 
and  discredit  the  view  that  the  tapetum  is  composed  of  fibres  of  the  corpus 
callosum. 

Section  of  the  corpus  callosum  (Muratow  J)  does  not  give  rise  to  degenera- 
tion of  the  tapetum,  whilst  lesions  of  the  frontal  lobe  of  the  same  side,  without 
doing  any  injury  to  the  corpus  callosum,  induce  degeneration  of  the  fibres 
which  pass  through  the  tapetum. 

The  occipito-frontal  bundle,  which  Dejerine  thinks  presents  a  fairly 
uniform  picture,  has  been  divided  by  German  authors,  such  as  Anton  and 
Zingerle,  into  separate  bundles.  One  of  these  has  been  specially  distinguished 
as  the  medial  longitudinal  bundle  of  Anton 2  (sub-calksal  of  Muratow).  The 
short  fibres  of  this  bundle  unite  the  frontal  cortical  areas  with  the  head  of  the 
caudate  nucleus,  whilst  the  long  fibres  reach  the  tapetum. 

Laterally  and  external  to  this  bundle  is  found  the  true  fronto-occipital 
fasciculus  of  Dejerine. 

Monakow' s  3  investigations  have  induced  him  to  accept  the  distinction 
of  the  fronto-occipital  bundle  into  three  well-differentiated  fasciculi.  One 
corresponds  to  the  medial  longitudinal  bundle  of  Anton,  a  second  to  the 
fronto-occipital  bundle  of  Dejerine  and  the  reticulo-cortical  bundle  of 
Obersteiner  and  Redlich,  whilst  the  third,  situated  laterally  and  below  the 
other  two,  appears  to  have  a  more  immediate  relation  with  the  Eolandic 
zone,  although  it  was  found  by  Monakow  as  a  separate  bundle. 

We  pass  now  to  the  question  whether  or  not  the  frontal  lobe  possesses 
projection  fibres  and  whether  these,  if  they  exist,  pass  through  the  internal 
capsule  (anterior  segment). 

Nearly  all  authorities  are  in  agreement  on  this  point. 

1 "  Sekund.  Degener,  nach  Durohschneid  d.  Balkens."    Neurol.  Centralb.    1892. 

2  Anton   and  Zingerle.     "  Bau,   Leistung  der   Menschlichen   Stirnhirns.     Fest- 
schrift des  Grazer  Universitdt.     1901. 

3  Monakow.     Gehirnkrankheiten.     1905.     Vol.  i. 


ASSOCIATIVE  PATHS  BETWEEN  FRONTAL  LOBE  &  CORTEX  201 

Monakow  states  that  the  anterior  tract  of  the  internal  capsule  contains 
projection  fibres  from  the  frontal  lobe,  so  that  all  the  convolutions  of  the 
cerebral  mantle,  including  those  of  the  frontal  lobe,  would  be  represented 
in  the  internal  capsule  by  means  of  fibres  of  the  respective  corona 
radiata. 

Through  the  anterior  tract  of  the  internal  capsule  there  would  pass  fibres 
coming  more  especially  from  the  corona  radiata  of  the  first  and  second 
frontal  convolutions — to  be  exact,  from  the  basal  portions  or  feet  of  these 
convolutions — and  these  would  lead  directly  to  the  cerebral  peduncle,  where 
they  would  come  to  form  a  part  of  the  mesial  tract.  Other  analogous  fibres 
would  proceed  to  the  pons  (fronto-pontine  paths).  A  third  bundle  would 
consist  of  fibres  leaving  the  foot  of  the  third  frontal  and  the  operculum  of 
the  ascending  frontal  convolution,  where  are  found  the  cortical  areas  of 
innervation  of  the  face,  tongue,  pharynx  and  larynx,  to  pass  down  in  the 
neighbourhood  of  the  genu  of  the  internal  capsule. 

Edinger  1  mentions,  although  he  does  not  describe,  a  bundle  which  he 
calls  the  tractus  fronto-pontine  zur  Brucke,  which  would  be  analogous  to  the 
temporo-pontine,  Rolandic-pontine,  etc. ,  tracts.  He  holds  that  the  function 
of  the  corona  radiata  is  to  connect  the  individual  apparatus  of  the  Neen- 
cephalon  with  the  various  apparatus  of  the  Palceencephalon.  The  figures 
shown  by  this  distinguished  anatomist  demonstrate  clearly  what  he  means. 
He  several  times  makes  use  of  the  phrase  :  Die  Bahnen  aus  dem  Stirnhirn  zur 
Brucke. 

Dejerine,2  in  the  second  volume  of  his  Anatomy,  repeats  the  notion  that 
the  constitution  of  the  anterior  segment  of  the  internal  capsule  includes 
fibres  which  come  from  the  orbital  and  external  surfaces  of  the  frontal  lobe. 
These  fibres,  he  thinks,  do  not  all  proceed  directly  to  the  anterior  segment 
of  the  capsule.  A  small  number  of  them  run  with  the  fronto-occipital  bundle 
and  surround  the  head  of  the  caudate  nucleus.  They  form  a  mixed  bundle 
composed  of  both  projection  and  association  fibres,  which  degenerate  in 
consequence  of  destructive  lesions  of  the  frontal  lobe. 

Of  the  clinical  cases  reported  by  Dejerine  that  of  Moriceau  is  very  interest- 
ing, but  it  is  to  be  remarked  that  the  frontal  foci  which  had  there  caused 
degeneration  in  the  anterior  segment  of  the  capsule  were  of  old  standing 
and,  indeed,  dated  back  ten  years  previously.  Schveigoffer's  case  of  partial 
degeneration  of  the  anterior  segment  of  the  capsule  is  not  quite  reliable 
because  the  focus  occupied  the  Rolandic  operculum,  and  it  is  generally 
agreed  that  the  fibres  in  this  area  are,  in  the  main,  projection  fibres. 

Another  bundle  of  fibres  of  the  anterior  segment  of  the  capsule  would 
appear  to  be  derived  from  the  frontal  convolutions  and  to  terminate  in  the 
mesial  and  lateral  nuclei  of  the  optic  thalamus.  The  frontal  lobe  would 
thus  come  into  relation  with  the  nuclei  of  the  optic  thalamus  through  the 
intermediary  of  the  internal  capsule. 

1  Edinger.     Einfuhrung  in  die  Lehre  vom  Bau  und  den   Verrichtungen  Nerven- 
systems.     1909. 

2  Dejerine.     Anatomie  des  centres  nerveux.     1901. 


202  THE  MECHANISM  OF  THE  BRAIN 

N.  Schukowski l  states  that  connections  are  set  up  between  the  frontal 
lobe  and  the  anterior  part  of  the  optic  thalamus  by  means  of  fibres  which 
course  through  the  anterior  segment  of  the  capsule  and  spread  out  into  the 
stratum  reticulatum  thalami.  This  author  is  convinced  that  similar  con- 
nections exist  between  the  frontal  lobe,  the  stratum  intermedium  and  the 
substantia  nigra  by  means  of  fibres  which  pass  through  the  genu  of  the 
internal  capsule  and  between  the  frontal  lobe,  the  internal  segment  of 
the  cerebral  peduncle,  and  the  nuclei  of  the  pons,  through  the  intermediary 
of  the  fronto-pontine  bundle. 

The  frontal  cortico-pontine  bundle,  according  to  Flechsig,  belongs 
to  the  third  system  of  sensory  bundles  of  the  internal  capsule,  and  goes  to 
form  the  inner  third  of  the  cerebral  peduncle.  This  bundle  would  terminate, 
in  great  measure,  in  the  grey  substance  of  the  pons.  According  to  this 
author,  however,  these  fibres  do  not  come  from  the  frontal  pole — that  is  to 
say,  from  the  true  anterior  associative  centre — but  from  those  areas  of  the 
frontal  convolutions  which  form  a  part  of  his  tactile  zone — i.e.  from  the 
feet  of  the  frontal  convolutions  (the  intermediate  motor  zone),  in  which  he, 
like  others,  has  observed  very  large  pyramidal  cells  which  give  origin  to  the 
fibres  of  ihefronto-protuberant  bundle,  and  more  especially  from  the  feet  of  the 
Rolandic  convolutions.  The  fibres  of  the  bundle  in  question  degenerate 
as  the  result  of  destructive  foci  in  this  region.  They  would,  therefore,  be 
the  motor  paths  for  the  muscles  of  the  neck,  trunk,  face,  larynx,  etc.,  and 
they,  by  means  of  the  thalamic  corona  radiata,  would  unite  the  cortex  to 
the  thalamus,  the  superior  cerebellar  peduncles,  the  island  of  Reil  and  the 
reticulate  substance.  This  bundle  would  correspond  to  a  large  extent  with 
the  geniculate  bundle. 

Quensel 2  confirms  -the  relations  of  the  frontal  lobe  with  the  anterior 
segment  of  the  internal  capsule  and  with  determined  nuclei  of  the  optic 
thalamus,  but  gives  a  different  interpretation  from  Dejerine  of  the  course 
and  relations  of  the  so-called  fronto-occipital  bundle. 

From  the  resume  of  his  work  which  he  gave  to  the  Congress  of  German 
Psychiatrists  and  Neurologists  in  Jena  in  1909,  one  cannot  form  any  accurate 
judgment  as  to  how  far  his  thesis  has  been  demonstrated.  The  author 
speaks  of  the  feet  of  the  frontal  convolutions  and  of  the  operculum  of  the 
ascending  frontal,  which,  from  physiological  and  functional  points  of  view, 
are  quite  distinct  from  the  frontal  and  pre-frontal  regions  with  which  we  are 
here  dealing  particularly.  The  bundle  in  question  has  been  described  as  an 
intellectual  or  psychic  bundle,  but  according  to  Dejerine3  and  Flechsig  it 
has  nothing  to  do  with  the  psychic  functions.  The  fibres  which  degenerate 
come  from  the  motor  zone,  the  para-Rolandic  lobule  and  the  immediately 
neighbouring  parts  of  the  frontal  lobe  (evolutionary  motor  zone). 

1 N.  Schukowski.  "  ttber  anatomische  Verbindungen  des  Frontallappen." 
Neurologisches  Centralblatt.  1897. 

2  Quensel.     Neurol.  Centralb.     1909. 

3  Dejerine.     Sur  Vorigine   corticale  et  le  trajet  intracerebral  des  fibres   de   Pelage 
inferieur  ou  pied  du  pedoncle  cerebral.     1894. 


ASSOCIATIVE  PATHS  BETWEEN  FRONTAL  LOBE  &  CORTEX  203 

On  the  question  of  the  relations  of  the  frontal  lobe  with  the  optic  thalamus 
there  still  remains  a  good  deal  of  doubt,  and  certainly  one  has  to  admit 
that  up  to  the  present  there  has  been  no  clear  demonstration  of  the 
interconnections. 

The  relations  between  the  frontal  lobes  and  the  caudate  nucleus  are  more 
definite. 

H.  Sachs l  describes  a  fasciculus  nuclei  caudati  which  unites  the  corpus 
striatum  with  the  cerebral  cortex  and  is  composed  of  fibres  derived  from  the 
frontal  lobe,  the  parietal  lobe  and  the  insula. 

Marinesco,2  applying  Marchi's  method  to  the  brains  of  monkeys  and 
dogs  which  had  suffered  mutilation  of  the  frontal  lobes  thirteen  to  twenty 
days  previously,  found  bundles  containing  degenerate  fibres  in  the  caudate 
nucleus  in  every  case. 

These  fibres  run  in  the  anterior  segment  of  the  internal  capsule  which 
they  then  leave  in  order  to  penetrate  the  caudate  nucleus.  Anatomical 
relations  between  the  frontal  lobe  and  the  corpus  striatum  have  been  noted 
by  Kolliker  and  Meynert.  It  is  to  Ramon  y  Cajal,3  however,  that  we  are 
indebted  for  the  first  positive  histological  proof  of  the  existence  of  these 
relations.  He  writes  as  follows : — "  From  all  regions  of  the  frontal  lobe 
situated  in  front  and  above  the  head  of  the  corpus  striatum  there  descend 
nervous  fibres  which  penetrate  the  corpus  striatum  and  unite  there  into 
small  bundles.  These  fibres  are  axis- cylinders  coming  from  the  small  and 
large  pyramidal  and  also  the  polymorphous  cells.  ..." 

In  this  connection  the  present  writer  has  carried  out  two  series  of  researches. 
The  first  dates  back  to  1897.  The  brains  investigated  were  those  of  monkeys 
which  had  been  operated  upon  many  months  before.  In  one  case  in  particular 
the  operation  took  place  eleven  months  before  the  autopsy.  In  all  cases  the 
operation  consisted  of  removal  of  both  frontal  lobes.4  The  second  series 
is  of  more  recent  date.  The  brains  were  those  of  monkeys  operated  upon 
eighteen  to  twenty  days  previously.  Marchi's  method  of  investigation  was 
employed.5 

In  the  first  series  sure  signs  of  degeneration  were  found : 
(1)  In  the  fronto- occipital  bundle  above  the  ependymal  substance,  just 
over  the  head  and  body  of  the  caudate  nucleus,  degenerate  fibres  running 
in  an  antero-posterior  direction.  In  this  region  the  degenerate  fibres,  readily 
recognisable  by  Weigert's  method,  are  intersected  at  an  acute  or  right  angle 
by  the  fibres  of  the  corpus  callosum  and  the  fibres  of  the  corona  radiata  of 
the  overlying  convolutions. 

In  one  of  the  preparations  (Fig.  57)  one  can  observe  a  pale  yellowish  grey 

1  H.  Sachs.      Vortrage  uber  den  Ban  und  die  Thatigkeit  des  Grosshirns.     Breslau, 
1893. 

2  Marinesco.     Societe  de  Biologic.     Fevrier,  1895. 
a  Cajal.     LaCellula.     1892. 

4  Bianchi,  L.     "  Le  degenerazioni  discendenti  endoemisferiche  consecutive  alle 
ablazioni  dei  lobi  frontali.     Ann.  di  Nev.     1897. 

5  International  Congress  of  Medicine,  Psychiatric  Section.     London,  1913. 


204  THE  MECHANISM  OF  THE  BRAIN 

area  at  the  base  of  the  corona  radiata  of  the  first  frontal  just  where  it  joins 
with  the  second  frontal  convolution,  Fo.  A  little  below  this  one  can  see 
normal  bundles  of  fibres,  coloured  blue,  just  at  the  commencement  of  the 
anterior  segment  of  the  capsule.  Neither  the  anterior  nor  the  posterior 
segment  shows  any  trace  of  degeneration. 

(2)  Still  further  below  and  more  externally,  at  a  point  just  above  and 
internal  to  the  upper  angle  of  the  fissure  of  Sylvius,  there  is  found  a  second 
yellowish  area  containing  a  large  number  of  degenerate  fibres  which  belong 
to  the  arcuate  bundle.  These  fibres  are  proceeding,  in  the  main,  to  the 
outermost  capsule,  the  daustrum,  and  some  to  the  putamen  of  the  lenticular 


Fig.  57 

Fo.  Fronto-occipital  bundle. — tin.  Cingulum. — ci:  Corona  radiata  with  marked 
degeneration.— la.  lacuna  of  disintegration.— Fee.  bundle  of  the  outermost 
capsule.— p.  Putamen 

nucleus.  Underneath  is  found  an  empty  space  closely  resembling  a  lacuna 
of  disintegration,  triangular  in  shape,  with  the  longest  line  or  base  looking 
towards  the  posterior  segment  of  the  internal  capsule.  It  is  a  true  lacuna 
and  it  comprises  the  upper  part  of  the  putamen  and  part  of  the  second 
segment  of  the  lenticular  nucleus.  The  external  wall  of  this  lacuna  is  com- 
posed of  the  bundle  of  fibres  of  the  outermost  capsule  which  establishes  a 
connection  between  the  first  temporal  convolution  and  the  frontal  operculum, 
following  the  bend  around  the  upper  angle  of  the  fissure  of  Sylvius  where  one 
can  see  distinctly  the  outlines  of  the  insula,  i  (Fig.  58).  No  other  lesion  is 
visible  at  this  level  except  a  certain  number  of  degenerate  fibres  in  the 
cingulum  (cin). 

The  injury  was  bilateral,  and  similar  lesions  of  the  putamen  (p)  were 
found  at  the  same  level  in  the  other  hemisphere,  only  much  more  limited. 
Degeneration  is  very  marked  near  the  upper  angle  of  the  lacuna,  outside  the 
anterior  segment  of  the  internal  capsule,  at  the  highest  point  of  the  curve 
described  by  the  corona  radiata  of  the  frontal  operculum  as  it  meets  with 
that  of  the  frontal  convolutions  (ta,  Fig.  58). 

Another  area  of  degeneration  is  visible  in  the  fronto- occipital  bundle 


ASSOCIATIVE  PATHS  BETWEEN  FKONTAL  LOBE  &  CORTEX  205 

(Fo)  above  the  head  of  the  caudate  nucleus.     The  anterior  segment  of  the 
internal  capsule  (da)  is  quite  intact.     The  same  degenerations  are  present 


Fig.  58 

Fo.  Occipital  frontal  bundle.— Fa.  Arcuate  bundle.— nc.  Caudate  nucleus.— 
ta.  Area  of  greater  degeneration. — i.  Insula. — s.  Fissure  of  Sylvius. — 
da.  Anterior  segment  of  capsule.— p.  Putaraen 

in  the  cingulum.    In  sections  posterior  to  those  represented  in  Figures  57 
and  58,  a  large  number  of  degenerate  fibres  are  found  in  the  tapetum. 

In  the  section  represented  by  Figure  59,  taken  from  the  brain  of  a  cebus 
killed  six  months  after  the  mutilation  and  stained  by  Weigert's  method,  one 
can  distinctly  observe  an  area  of  degeneration,  intersected  by  normal  fibres 


Fig.  59 

Fo.  Pronto-occipital  bundle. — da.  Anterior  segment  of  internal  capsule. — 
a.  Claustrum 

of  the  corpus  callosum,  which  corresponds  with  the  fronto- occipital  bundle 
(Fo) .  There  is  also  another  area  of  more  marked  degeneration  in  the  situation 
of  the  arcuate  bundle,  the  fibres  of  which  are  proceeding  to  the  claustrum 
(a),  the  outermost  capsule  and  the  external  capsule.  In  this  section,  as  in 
others  at  the  same  level,  stained  by  carmine,  the  anterior  segment  of  the 
internal  capsule  is  seen  to  be  without  trace  of  degeneration. 
Investigation  by  Marchi's  method  confirmed  these  findings. 


206  THE  MECHANISM  OF  THE  BRAIN 

Degeneration  of  the  cingulum  has  not  been  a  frequent  finding.  It  was 
found  to  be  more  marked  in  the  case  of  one  monkey  in  which  damage  had 
been  done  on  the  internal  surface  of  the  frontal  lobe,  not  only  to  the  superior 
frontal  convolution  but  also  to  a  part  of  the  limbic  convolution  in  front  of 
the  genu  of  the  corpus  callosum. 

Degeneration  of  the  superior  longitudinal  or  arcuate  bundle  and  of  the 
fr  onto -occipital  bundle  has  been  a  constant  finding  in  the  case  of  brains 
in  which  the  destruction  of  the  frontal  lobes  involved  a  large  extent  of  the 
external  surface  in  front  of  the  so-called  intermediate  motor  zone. 

In  this  second  series  of  observations  one  readily  observes  the  degeneration 
limited  to  the  two  quite  distinct  bundles  above  mentioned.  One  is  found 


nn  c 


Fig.  60 

Fo.  Pronto-occipital  bundle.— cc.  Corpus  callosum.—  nnc.  Caudate  nucleus.— 
Fa.  Fibres  of  arcuate  bundle  which  penetrate  the  claustrum  and  runs 
in  the  external  and  outermost  capsules 

above  and  to  the  outside  of  the  angle  of  the  lateral  ventricle,  hence  above 
the  head  of  the  caudate  nucleus.  This  bundle  is  represented  by  a  dark  area 
about  2  mm.  high  and  1  mm.  broad  (Fo,  Fig.  60),  which  is  seen  under  the 
lower  powers  of  the  microscope  to  furnish  some  fibres  which  penetrate  the 
head  of  the  caudate  nucleus,  whilst  the  superior  part  of  the  bundle  runs 
above  the  head  of  the  nucleus. 

The  other  bundle  is  found  in  the  course  of  the  external  capsule  and  the 
outermost  capsule  and  also  occupies  the  grey  substance  of  the  claustrum 
(Fa,  Figs.  60  and  61).  As  far  as  the  level  indicated  in  Figure  61  by  the  line 
da,  the  anterior  segment  of  the  internal  capsule  shows  no  degenerate  fibres. 

Figure  61  reproduces  a  section  from  the  frontal  lobe  of  a  cebus  which 
underwent  mutilation  of  the  external  surface  of  the  frontal  lobe  in  front  of 
the  intermediate  motor  zone.  It  shows  an  area  of  degeneration  situated 
in  the  fronto- occipital  bundle  (Fo)  and  a  line  of  degeneration  along  the  length 
of  the  claustrum  and  involving  also  a  part  of  the  external  capsule.  No 
degenerative  fibres  are  found  in  the  cingulum  (c)  (the  internal  surface  of  the 
hemisphere  had  been  spared).  Under  high  magnification  one  can  observe 


ASSOCIATIVE  PATHS  BETWEEN  FRONTAL  LOBE  &  CORTEX   207 

small  offshoots  from  Fo  in  the  head  of  the  caudate  nucleus  (nc)  at  its  upper 
and  outer  corner.  The  anterior  segment  of  the  internal  capsule  (da)  shows 
no  trace  of  degeneration. 

Figure  62,  which  is  an  exact  photographic  reproduction,  furnishes  further 
confirmation  of  the  fact  that  the  two  areas  of  degeneration  mentioned  are 


cia 


Fig.  61 

Fo.  Area  of  degeneration  of  fronto-occipital  bundle. — c.  Cingulum. — nc.  Cau- 
date nucleus. — cia.  Internal  capsule,  anterior  segment.— a.  Area  of 
degeneration  in  the  claustrum.—  i.  Insula 

the  only  ones  which  can  be  detected  by  this  method  of  investigation  (Fig. 
62,  Fo  and  Fa). 

From  these  researches  it  seems  to  the  writer  to  be  fairly  well  established 
that  the  frontal  lobe,  or  rather,  that  part  of  it  which  lies  in  front  of  the 


Fig.  62 

Fo  Fo.  Area  of  fronto-occipital   bundle. — cia.  Anterior  segment  of  interna 
capsule.—  Fa.  Area  of  degeneration  of  arcuate  bundle  in  site  of  claustrum 

intermediate  motor  one,  has  no  direct  relations  with  the  optic  thalamus 
through  the  internal  capsule.  It  evidently  has  distinct  relations  with  the 
head  of  the  caudate  nucleus  and  it  is  fairly  clear  that  it  has  some  relations 
with  the  putamen  of  the  lenticular  nucleus  and  with  the  claustrum.  Besides 
being  associated  with  the  motor  zone  it  is  especially  associated  with  the  whole 
sensory  mantle  by  means  of  the  fibres  of  the  fronto-occipital  and  arcuate 
bundles.  If,  as  Dejerine  and  Monakow  claim  to  have  demonstrated,  these 


208  THE  MECHANISM  OF  THE  BRAIN 

same  bundles  contain  fibres  which  degenerate  as  the  result  of  occipital  and 
temporal  mutilations,  this  would  afford  proof  of  the  reciprocal  associative 
relations  that  subsist  between  the  frontal  lobe  and  the  sensory  areas,  more 
especially  the  tactile,  the  visual  and  the  auditory.  The  cingulum  and  at 
least  a  part  of  the  unoinate  bundle  would  establish  communications  between 
the  frontal  lobe,  the  limbic  lobe,  and  the  sphenoidal  pole,  including  the  unc.us, 
which  is  probably  a  centre  of  taste.  It  would  thus  appear  that  the  frontal 
lobe  has  acquired  paths  of  communication  (associative)  with  all  the  sensory 
fields  of  the  mantle. 

The  exchange  of  fibres  is  reciprocal,  as  already  mentioned. 

The  writer's  investigations  do  not  confirm  the  existence  of  fronto-thalamic 
fibres,  and  in  the  absence  of  proof  he  cannot  associate  himself  with  those 
who  admit  a  direct  relation  with  the  optic  thalamus,  except  in  so  far  as  he 
has  been  able  to  draw  certain  inferences  from  preparations  taken  from  a  brain 
in  which  the  lesion  had  fallen  too  far  behind  and  had  involved  the  inter- 
mediate motor  area  along  with  a  portion  of  the  anterior  Rolandic  convolution, 
in  which  case  he  found  a  small  degenerate  bundle  in  the  internal  capsule. 

We  do  not  yet  know  very  much  of  the  function  of  the  nuclei  of  the  corpus 
striatum,  and  rather  than  formulate  any  hypothesis  it  is  preferable  to  wait 
until  new  experimental  and  histological  studies  clear  up  the  nature  of  these 
relations. 

The  relations  supposed  to  exist  between  the  frontal  and  pre-frontal  area 
of  the  frontal  lobe,  with  the  pons,  the  cerebral  peduncle,  and  the  cerebellum, 
must  still  remain  fields  open  to  investigation.  For  the  moment,  everything 
tends  to  show  that  the  degenerations  which  form  the  basis  of  these  supposed 
relations  were  the  effect  of  lesions  of  the  motor  zone  or  were  of  too  old 
standing. 

Anatomico-histological  findings  thus  furnish  us  with  another  non- 
negligible  proof  of  the  functions  of  the  frontal  lobes.  The  associative  paths 
that  unite  the  sensory  cortex  with  the  frontal  lobes  have  a  twofold  office  : 
first,  that  of  informing  the  higher  consciousness  of  the  modifications  of  the 
kinsesthesis  and  of  all  the  new  percepts  acquired  by  the  personality  by  means 
of  the  sensory  centres  ;  second,  that  of  permitting  the  higher  consciousness 
to  select  and  recall  those  images  registered  in  the  sensory  cortex  that,  in  the 
vicissitudes  of  mental  and  physical  life,  are  reputed  necessary  for  the  purposes 
of  the  struggle  for  existence  and  for  higher  reasoning  which,  directly  or 
indirectly,  displays  biophylactic  virtues  and  determines  particular  lines  of 
conduct. 

That  the  function  is  of  this  nature  can  be  inferred  not  only  from  experi- 
mental inquiries  but  also  from  reliable  clinical  observations.  Its  more 
intimate  mechanism  will  be  made  clearer  in  the  following  chapters  upon 
intelligence,  emotions  and  consciousness. 


CHAPTER  VIII 

Intelligence  and  Language 

IT  is  not  the  object  of  this  work  to  treat  of  intelligence  after  the  manner  of 
the  philosophers.  It  is  altogether  beyond  the  province  of  the  biologist  to 
push  his  inquiries  into  fields  of  abstract  thought.  Not  by  any  means  that 
the  writer  would  desire  to  detract  from  the  value  of  the  monumental,  though 
not  wholly  eurithmic  edifice  raised  by  philosophy  to  intellect,  throughout 
all  the  evolutionary  phases  of  philosophic  thought  from  the  time  of  the 
earliest  civilisation  until  to-day.  To  others  the  task  of  dedicating  themselves 
to  that  labour,  which  no  doubt  has  often  been  the  happy  creator  of  mental 
formulse  ;  a  labour  to  which,  from  the  earliest  dawn  of  civilisation,  the 
human  spirit,  represented  by  the  intellectual  elite  of  every  epoch,  embracing 
the  culture  of  the  time  and  the  genius  of  each  stock,  has  devoted  all  its 
energies  in  an  anxious  inquiry  into  the  causes,  origin  and  nature  of  thought 
and  of  the  ego.  In  this  field  the  philosopher  is  quite  free  to  exercise  all  the 
powers  of  fantasy  and  of  logic,  either  creative  or  dialectic.  He  may  follow 
up  the  principle  of  causality  and  penetrate  deeply  into  the  mystic  regions 
of  theological  metaphysics.  He  is  free  to  invoke  the  force  that  is  intrinsic 
in  matter,  or,  if  he  care,  a  creative  being.  His  dominion  is  the  immensity 
of  the  unknown,  into  the  obscurity  of  which  he,  fervent  upholder  as  he 
may  be  of  a  particular  doctrine  or  system,  sheds  the  light  of  his  intellect, 
sometimes  genial  and  creative,  as  he  confronts  and  penetrates  the  unsolved 
problems  of  existence  and  of  man's  history. 

Comparative  psychology  with  the  abundant  harvest  it  has  gathered  by 
following  up  the  evolution  of  mind  from  infancy  to  maturity,  from  the  savage 
to  the  modern  civilised  man ;  the  facts  furnished  by  the  process  of  mental 
dissolution,  caused  by  the  most  varied  morbid  processes  in  the  brain,  both 
localised  and  diffuse  ;  the  rich  store  of  knowledge  culled  from  the  study  of 
the  evolutionary  arrests  of  the  human  brain  as  contrasted  with  the  various 
phases  of  normal  evolution  ;  all  the  conquests  which  biology,  and  more 
especially  neurology,  have  won  and  brought  to  bear  upon  the  dispute  between 
the  ancient  dominion  of  speculation  and  the  inquiring  spirit  which  seeks  to 
penetrate  nature,  making  use  of,  and  perfecting  in  the  course  of  inquiry,  the 
very  instruments  (senses  and  brain)  which  Nature  herself  elaborates ;  all 
these  warrant  us  in  remaining  within  the  domain  of  scientific  positivism, 
drawing  from  objective  observation  those  conclusions  which  best  reflect 
reality,  as  it  is  perceived. 

It  is  certainly  true,  as  already  mentioned  in  Chapter  IV. ,  that  comparative 
psychology  has  to-day  taken  its  place  of  honour  amongst  our  studies  and 
conclusions. 

0  209 


210  THE  MECHANISM  OF  THE  BRAIN 

Some  naturalists,  caught  in  the  throes  of  religious  sentiment,  are  prepared 
to  recognise  a  species  of  mind  in  animals,  but  interpose  between  the  animal 
and  the  human  mind  an  insurmountable  barrier — the  reflex  nature  of  the 
manifestations  of  mental  life  and  the  absence  of  language  in  the  higher 
mammals,  highly  evolved  though  they  be. 

Language  is  necessary  for  the  more  complex  and  longer  reasoning  pro- 
cesses, but  not  for  the  more  immediate,  simple  and  short  reasonings.  It  is 
difficult  to  understand  why  any  unprejudiced  observer  should  find  himself 
in  difficulty  before  such  a  barrier.  The  idea  expressed  by  Bain1  is  very 
applicable  to  the  scale  (phylogenetic)  of  mental  life.  "  We  ha,ve  every  reason 
for  believing,"  he  writes,  "that  there  is,  in  company  with  all  our  mental 
processes,  an  unbroken  material  succession." 

The  naturalist  who  is  so  constituted  in  mind  as  to  be  attracted  into  fields 
of  metaphysical  thought  must  lose  the  psychic  attitude  that  is  characteristic 
of  the  biologist.  Metaphysical  abstraction,  the  product  of  fantasy  and  of 
logic,  is  far  removed  from  objective  reality  and  from  what  appears  as  such 
to  our  senses,  and  in  any  case  it  is  insufficient  to  furnish  us  with  elements 
that  will  serve  as  a  key  to  the  positive  cognitions.  The  biologist  cannot  go 
beyond  abstractions  which,  being  founded  on  connected  series  of  observations 
and  deductions,  still  maintain  contact  with  facts  and  retain  their  fundamental 
character  of  objectivity. 

Hence  it  comes  that  we  have  formulated  a  conception  of  life,  intelligence, 
morality  and  sociality  that  is  quite  independent  of  any  abstract  notions, 
arrived  at  solely  by  a  process  of  reasoning. 

As  biologists,  e.g.,  we  do  not  feel  called  upon  to  examine  the  form  or 
mode  of  reasoning  in  order  to  draw  metaphysical  conclusions  or  lay  down 
the  norms  that  regulate  the  reasoning  process  (logic) .  To  us  the  important 
points  in  the  argument,  points  which  should  be  clearly  set  forth,  are  as 
follows  : — (1)  That  the  intellect  is  in  continuous  evolution  ;  (2)  that  this  is 
proportionate  to  the  development  and  perfecting  of  the  senses,  in  so  far  as 
these  furnish  an  ever-increasing  number  of  cognitions  which  are  elements 
capable  of  being  utilised  for  new  and  more  complex  mental  formations ; 
(3)  that  the  perfecting  of  the  senses,  which  supply  the  positive  cognitions, 
coincides  with  the  evolution  of  the  brain  ;  (4)  that  it  follows  that  intellect 
is  variable  and  not  exempt  from  the  law  of  time  and  quantity  ;  (5)  that  the 
mental  syntheses  themselves  have  likewise  a  variable  value,  according  to 
the  greater  or  lesser  number  of  elements  which  go  to  make  up  the  mental 
constructions,  the  latter  being  dependent  upon  the  power  of  combination 
and  association  (conjunctive  imagination),  which  in  turn  is  conditioned  by 
the  faculty  of  reproducing  rapidly  and  faithfully,  by  unconscious  processes, 
the  mnemonic  traces  of  percepts,  judgments,  psychic  complexes  and  past 
experiences  ;  (6)  that  this  associative  process  is  based,  as  daily  becomes  more 
evident,  on  the  number  of  evolved  cells  in  the  mantle,  and  hence  on  the 
multiple  paths  of  association  (myelinised  fibres  and  neurofibrils) ,  the  number 
of  which  far  surpasses  even  the  most  imaginative  limits  of  calculation. 
1  Bain.  Mind  and  Body.  1873. 


INTELLIGENCE  AND  LANGUAGE  211 

The  biologist  has  no  need  to  fall  back  upon  dialectics  in  order  to  support 
his  contention.  He  does  not  set  out  with  the  express  object  of  bolstering 
up  a  preconception  with  arguments  which,  however  skilful  they  be,  are  but 
excogitations  intended  to  demonstrate  the  "  necessary  truth  "  or  "  the  only 
possible  solution  "  ;  nor  is  he  obliged  to  distort  facts  in  order  to  make  them 
fit  in  with,  preconceived  notions.  Much  less  can  the  biologist  be  guided 
by  motives  of  an  affective  order  which,  generally  speaking,  are  of  a  religious 
nature.  As  E.  Eignano  l  says,  it  is  always  the  religious  element  which  is  at 
the  bottom  of  every  metaphysical  speculation  whether  we  are  conscious  of 
it  or  not.  This  assertion  may  be  rather  absolute,  but  nevertheless  the  fact 
remains  that  the  affective  element  predisposes  to  affective  reasonings  and  to  a 
variety  of  extra-logical  deductions  (Ribot 2) — i.e.  to  theses  or  to  preconcep- 
tions which  do  not  correspond  with  objective  reality.  We  find  examples 
of  this  in  the  attitude  of  some  religious  naturalists,  especially  in  Germany, 
in  their  opposition  to  the  Darwinian  doctrines  (Ecker) . 

The  metaphysical  attributes  of  the  Divinity  are,  as  James  3  says,  a  pure 
verbalism  or  a  professionalism,  substituted  for  the  sensible  images  of  the  real 
facts  of  life.  ^ 

All  preconceived  dogmatisms  of  affective  origin  lie  quite  without  the 
fields  of  observation  which  give  scope  to  the  work  and  thought  of  the  biologist. 
The  dignity  of  experimental  science  is  in  no  way  lessened  by  the  fact  that 
its  teachings  alter  from  time  to  time  and  that  new  doctrines  are  substituted 
for  old.     The  doctrines  are  renewed  like  molecules  within  the  cells,  like  cells 
with  the  organism.     As  the  cell  and  the  organism  evolve  and  become  perfected 
so  the  science  of  life  is  evolved  and  perfected,  maintaining  its  individuality 
all  along  because  it  always  has  this  characteristic — that  it  is  pivoted  on  the 
rigorous  investigation  of  facts,  which  enlarge  the  field  of  inquiry  and  involve 
the  modification  and  perfecting  of  methods  and  technique.     On  the  other 
hand,  it  is  to  be  pointed  out  that  it  is  not  only  biological  doctrines  which 
change.     New  discoveries   may  demolish  a   doctrine,   but  this  generally 
represents  a  historical  point  in  the  evolution  of  the  knowledge  of  life.     Some- 
times  they  represent  polemic  fields  which  serve  as  points  of  departure  for 
new  inquiries  by  means  of  which  we  arrive  at  higher  levels  of  knowledge. 
At  bottom,  we  strive  to  define  facts  and  phenomena,  to  discover  their  genesis, 
to  trace  their  relations  with  other  facts  and  phenomena,  to  establish  ever 
more  intimate  relations  with  all  the  other  natural  sciences,  with  Physics, 
Chemistry,  Palaeontology,  Zoology,  and  especially  Comparative  Anatomy 
and  Comparative  Psychology.     The  biologist — and  consequently  the  psy- 
chologist, who  is  concerned  with  the  higher  manifestations  of  life — does  not 
pursue  pre-established  aims  or  subjective  aspirations,  and  much  less  does  he 
feel  constrained  to  establish  a  prime  cause  or  an  intelligent,  willing  author  of 
the  creation  of  the  world.    Sufficient  to  the  biologist  is  the  point  of  departure 
that  life  is  a  cosmic  phenomenon  and  intelligence  a  phenomenon  of  life. 

1  Rignano.     II  ragionamento  internazionale.     Scientia,  1915. 

2  Ribot.     La  logique  des  sentiments.     1905. 

3  James.     The  Varieties  of  Religious  Experience.     1916. 


212  THE  MECHANISM  OF  THE  BRAIN 

If  the  facts  accumulated  by  biology  warrant  the  conclusions  above  men- 
tioned, it  necessarily  follows  that  intelligence  and  consciousness  are  not  exempt 
from  the  general  laws  that  apply  to  cosmic  energy  and  hence  to  quantity. 

Although  Bergson,1  one  of  the  most  acute  of  modern  philosophers,  refuses 
to  recognise  quantity  within  the  sphere  of  psychic  phenomena,  it  seems  to  the 
writer  that  it  must  be  regarded  as  an  integral  element.  One  cannot  conceive 
a  quantitatively  static  condition  of  intelligence,  unless  under  exceptional 
individual  circumstances.  The  movement  of  images  with  their  emotional 
content  and  the  constant  succession  of  external  stimuli  differing  in  quantity, 
nature  and  intensity  must  necessarily  induce  not  only  qualitative  but  also 
quantitative  modifications  of  the  intelligence.  If,  e.g.,  an  individual  has  a 
perceptive  capacity  by  which  he  receives  and  fixes  a  number  of  stimuli  equal, 
let  us  say,  to  ten,  whilst  another  individual  under  the  same  conditions  of 
environment  receives  and  fixes  five,  it  is  evident  that  the  two  intellects  differ, 
especially  because  the  quantitative  denominator  is  not  the  same,  and  one 
can  understand  that  with  a  variation  in  the  quantity  of  elements  there  is 
also  a  difference  in  the  qualitative  exponent. 

If  the  first  individual  assimilates  with  his  consciousness  the  contents  of 
the  ten  perceptions,  associating  and  fusing  them  with  his  pre-existing  mental 
capital,  elaborating  them  into  more  complex  mental  products  which  may 
even  appear  as  inventions,  whilst  the  other  individual  does  not  assimilate, 
but,  rather,  forgets,  all  or  some  of  his  five  percepts,  then  undoubtedly  the 
two  intellects  will  be  qualitatively  different,  but  the  reason  for  this  will  lie 
especially  in  the  different  quantities.  The  most  irrefutable  proof  in  this 
connection  is  furnished  by  the  facts  of  mental  evolution  in  children.  Every 
year  at  school,  every  month,  every  day,  perhaps,  supplies  new  material  to 
the  evolving  intelligence.  New  elements  develop  its  creative  power,  new 
horizons  appear  before  it,  and  from  its  increasing  energies  there  emanate 
diverse  forms  of  reaction  (conduct).  It  is  evident  that  the  quantity  of 
cognitions  and  adequate  reactions  emanating  therefrom  impress  a  certain 
intonation  on  consciousness,  which  in  its  growth  and  development  not  only 
exhibits  features  of  quality  but  is  at  the  same  time  essentially  quantitative. 
One  can  agree  with  Masci  2  when  he  holds  that  mutations  of  consciousness 
resulting  from  intensity  of  feeling,  emotionability,  reactivity,  in  direct  or 
inverse  ratio  with  the  quantity  of  utilisable  imaginative  content  in  a  given 
unit  of  time,  cannot  be  expressed  in  numbers  or  in  units  of  space,  and  that, 
with  the  exception  of  the  reaction,  they  remain  subjective  facts ;  but  this 
does  not  take  away  the  quantitative  character  from  these  facts,  any  more 
than  it  takes  away  the  qualitative  factor.  Works  of  art  offer  an  argument 
against  the  idealistic  indeterminism  of  the  Bergsonian  philosophy,  because 
in  many  of  these,  so  long  as  they  are  not  simply  reflex  copies  of  nature  but 
reproduce  states  of  mind,  there  is  projected  the  quantity  of  feeling  and  of 
the  intellectual  content. 

1  Bergson.     La  evoluzione  creatrice.     1907. 

2  Macoi.     "  Quantita  e  misura  del  fenomeni  psichici."     Accad.  Reale  di  Scienze 
morali  e  politiche.     Naples,  1915. 


INTELLIGENCE  AND  LANGUAGE  213 

Grief  which,  afflicts,  pity  which  tempers  and  mellows,  love  which  exalts, 
and  jealousy  which  destroys,  are  not  only  qualitative  states  but  also 
expressive  of  ideative  and  emotional  quantity. 

The  muscular  human  figures  depicted  on  the  vault  of  the  Sistine  Chapel 
reveal  the  strong  feeling  and  immense,  historical,  mental  content  of  Michel- 
angelo. Lord  Byron's  description  of  the  embrace  in  Parisina,  and  the 
suicidal  jealousy  of  Othello,  represent  not  only  qualities  of  mind  but,  at  the 
same  time,  quantities  that  may  even  determine  criminal  action  of  the  most 
tragic  kind. 

Consciousness  makes  us  aware  not  only  of  the  quality  of  the  emotions 
but  also  of  the  ideative  content  and  of  the  intensity  of  feeling.  It  is  of  no 
consequence  that  we  possess  no  means  of  measuring  these  grades  of  feeling. 
At  the  same  time,  the  graphic  method  employed  by  Mosso,  Patrizi  and 
others,  in  the  investigation  of  the  emotions  and  the  study  of  morbid  con- 
ditions, serve  to  strengthen  this  view.  One  may  recall,  e.g.,  the  affectionate 
mother  mentioned  in  Chapter  I.  who,  exhausted  and  anaemic  as  the  result 
of  prolonged  lactations  and  hardships  in  life,  fell  into  a  state  of  neurasthenia, 
of  which  the  principal  symptom  was  a  profound  disturbance  of  the  kinsesthetic 
sense  with  the  disappearance  of  the  sentiment  of  affection  for  her  sons. 
"  I  would  like,"  she  said,  "  to  feel  the  joy  of  the  immense  affection  which  I 
had  for  them,  but  now  I  feel  quite  indifferent.  I  have  a  great  void  in  my 
consciousness.  I  feel  that  I  cannot  live."  In  this  way  arose  the  idea  of 
suicide,  symbol  of  the  enormous  reduction  of  the  maternal  personality. 

It  is  obvious  that  in  a  case  of  this  kind  we  cannot  speak  solely  of  quality. 
We  have  here  to  deal  with  a  component  which  was  a  part  of  the  personality, 
and  it  is  needless  to  confuse  the  two  phenomena  by  asserting  that  the  quality 
gives  the  illusion  of  quantity. 

The  dement,  whose  mental  capital  we  see  failing  every  day,  furnishes  us 
with  clear  proof  of  the  quantitative  factor. 

The  capital  of  ideas  is  a  quantity  and  the  progressive  loss  of  ideas,  such 
as  we  observe  in  Progressive  General  Paralysis,  is  a  phenomenon  of  quantity. 
It  is  undoubtedly  true  that  this  phenomenon  is  accompanied  by  qualitative 
changes  ;  the  ideas  are  less  clear,  possess  less  determinative  power,  have  lost 
their  colouring  and  their  affective  tone,  so  that  interest  comes  to  fail ;  but 
all  this  which  seems  quality  can  be  reduced  to  quantity  ;  the  colouring  and 
tone  of  ideas  is  given  by  their  number,  by  their  association  and  by  the 
affective  element,  those  all  making  for  a  strong  resonance  in  consciousness. 

Indifference  towards  those  ideals  which  once  stirred  us  and  excited  our 
enthusiasm  to  such  an  extent  as  to  lead  us  to  sacrifice  our  personal  interests 
and  risk  our  very  lives  is  a  matter  of  intensity,  just  as  quantity  of  electricity 
in  ratio  to  resistance  gives  us  a  light  of  greater  or  less  intensity.  The  qualita- 
tive factor  is  by  no  means  to  be  excluded ;  it  is,  rather,  the  more  obvious 
thing,  but  if  we  push  our  inquiries  further  we  find  that  it  depends  upon 
quantity. 

From  this  point  of  view  it  seems  clear  that  psychic  energy  (intellectual 
force)  is  not  exempt  from  the  universal  laws  which  regulate  the  other  energies 


214  THE  MECHANISM  OF  THE  BKAIN 

of  nature.    If  we  indicate  quantity  by  q,  resistance  by  r,  and  the  product  by 

q 
n,  we  can  make  the  following  equation: —  ~=n. 

The  efficacy  of  the  conduct  of  a  man  or  a  country  is  proportionate  to  the 
mental  quantity  (thought,  sentiments,  will)  available  for  the  overcoming  of 
external  resistances  (popular  habits  and  the  impulses  of  other  peoples)  and 
the  internal  resistances  of  all  the  cerebral  and  extra-cerebral  organs  con- 
cerned, which  are  represented  in  consciousness  by  doubt,  by  fear,  by  difficulties 
which  appear  insuperable,  and  generally  end  in  observance  of  the  law  of 
inertia  (the  dokefar  niente). 

Intelligence,  then,  is  a  biological  fact.  Thought  is  a  dynamic  pheno- 
menon of  life,  for  it  arises  essentially  from  the  power  which  the  higher  living 
beings,  in  whom  nervous  tissue  is  developed  and  differentiated,  possess  of 
spiritualising,  to  a  greater  or  less  extent,  the  world  in  which  they  live,  the 
power  to  fix  its  images,  to  construct  syntheses  of  these  (from  the  most  simple 
to  the  most  complex  judgments),  to  combine  in  the  most  diverse  manner  the 
products  of  the  perceptions  and  their  derivatives  with  the  modifications  of  the 
self,  and  with  the  reactions  upon  the  world,  whence  is  derived  what  we  call 
experience.  So  it  comes  about  that  experience  becomes  ever  more  the 
safeguard  of  existence,  which  follows  the  law  of  adaptation  to  the  environ- 
ment, accompanied  by  an  incalculable  series  of  reactions.  Some  of  these 
are  stabilised  by  the  physical  and  social  environment  itself  ;  others  vary 
ad  infinitum  in  different  individuals,  in  proportion  as  we  get  perfecting  of 
the  perceptive  process,  which  is  the  basis  of  intelligence,  elaborated  more 
and  more  by  a  perennial  flow  of  old  and  new  material.  Thought  is  not  a 
faculty,  it  is  a  complex  functional  product  elaborated  by  co-operation  of 
various  functions  and  processes — transformation  of  external  stimuli  into 
images  (perception) ;  fixation  and  conservation  of  these  images  ;  construction, 
with  the  images,  of  mental  complexes  in  series  (to  the  constitution  and  number 
of  which  no  calculation  or  mathematical  formula  is  applicable)  ;  the  modifica- 
tions of  the  ego  under  the  influence  of  cosmic  and  social  stimuli  (emotions  and 
sentiments). 

The  biological  conception  of  intelligence  conflicts  strongly  with  rational- 
istic intellectualism,  which  is  founded  upon  an  aprioristic  conception.  Indeed, 
when  submitted  to  a  methodical  process  of  analysis,  intelligence  always 
appears  before  us  as  a  complex  vital  phenomenon  with  an  anatomical  basis. 

It  is  not  a  unitary  function,  as  some  think,  because  if  we  take  into  account 
the  diversity  of  the  elements  and  processes  from  which  it  results  (perceiving, 
feeling,  associating,  reacting),  we  find  a  corresponding  variation  in  the 
anatomical  bases,  which  comprise  all  the  brain  already  differentiated,  in  the 
sense  explained  in  the  first  chapter  of  this  book. 

From  sensation  to  intellect,  from  reflex  to  voluntary  movement  and  to 
individual  and  collective  conduct,  considered  as  a  whole,  there  is  nothing 
more  than  a  series  of  processes  which  are  resolved  into  movements,  identical 
in  nature 1  but  extending  from  the  most  simple  to  the  most  complicated t 

1  Morselli.     Manuale  di  Semiotica  delle  malattie  mentali.     1894. 


INTELLIGENCE  AND  LANGUAGE  215 

movements  which  obey  the  fundamental  law  of  evolution  on  one  band 
(genetic  psychology),  and  that  of  adaptation  on  the  other.  Thought, 
therefore,  is  not  an  abstract  reality,  as  has  been  represented,  but  a  physio- 
logical fact,  inasmuch  as  it  is  the  product  of  the  function  of  an  organ  which 
may  be  regarded  as  the  result  of  the  highest  grade  of  evolution  of  matter. 


* 
*  * 


Life  is  an  impulse  and  a  defence,  and  intelligence,  with  its  power  of 
penetration  into  the  cosmic  and  social  environment  and  its  powers  of  defence 
and  adaptation,  is  also  a  biophylactic  function.  To  penetrate  the  world 
in  which  we  live  signifies  to  know  it.  To  know  it,  signifies  to  make  use  of 
its  energies  so  as  to  promote,  in  every  possible  way,  the  integration  of  the 
individual  and  the  species,  and  to  defend  oneself  from  all  that  may  be  inimical 
to  the  one  or  the  other.  Keality  does  not  immediately  obtrude  itself  on  our 
senses,  nor  is  it  at  once  perceived  ;  it  is  not  directly  and  intuitively  divined 
and  classified  as  such  by  the  intellect,  but  rather  does  it  become  known  to 
us  through  individual  (ontogenetic)  and  inherited  (phylogenetic)  experience. 
Experience  passes  through  evolutionary  phases,  the  earliest  of  which  may 
be  traced  in  the  obscurity  of  the  unconscious  and  elaboration  of  the  nervous 
apparatus  under  the  repeated  action  of  stimuli,  these  becoming  summed 
together  until  they  acquire  the  intensity  necessary  to  overcome  the  threshold 
of  conscious  perception.  One  can  convince  oneself  of  the  reality  of  a  pre- 
paratory phase  if  one  analyses  the  evolutionary  progress  of  a  civilised  people 
(social  phylogenesis),  or,  again,  if  one  investigates  the  evolution  of  the 
individual  (perceptive  ontogenesis).  Many  realities  only  become  apparent 
after  long  examination.  Repetition  of  the  stimulus  and  observative  analysis 
are  factors  which  prepare  the  way  for  the  apperceptive  process. 

The  savage  and  the  untutored  member  of  an  advanced  society  do  not 
e.g.,  observe  the  filthy,  full  perception  of  which  determines  eliminating  actions 
that  become  defensive  of  the  personal  and  collective  integrity  and  conducive 
to  health,  which  is  the  fundamental  attribute  to  which  the  living  organism 
unconsciously  aspires.  Herein  we  see  the  esthetic  sentiment  developing  and 
coming  into  play  as  a  new  component  of  the  consciousness  of  the  individual 
or  of  a  civilised  community.  One  must  agree  that  thought  is  not  always 
conscious,  although  it  is  often  directed  by  consciousness.  If  we  look  upon 
intelligence  not  as  a  faculty  of  the  mind  but  as  the  dynamic  result  of  the 
notions  and  experiences  accumulated  through  the  mechanism  of  the  organs 
of  the  senses,  it  seems  quite  clear  that  this  product  is  already  logically 
disposed  in  the  archives  of  the  memory  and  of  the  subconscious,  according 
to  the  natural  order  of  the  world  perceived  and  of  the  experience  of  the  ego 
which  created  and  is  perennially  creating  it  in  the  same  logical  order  as  in 
objective  reality,  with  all  its  relations  and  its  successions.  If,  then,  it  is  true, 
as  Ingenieros 1  and  others  have  asserted,  that  the  psychic  functions  are  not 
always  conscious,  it  is  equally  true  that  the  keeping  of  an  objective  firmly  in 
view  is  a  fact  of  consciousness  ;  round  that,  objective  thought  is  developed 

1  Ingenieros.     Principios  de  Psichologia  Biologica.     Madrid,  1913. 


216  THE  MECHANISM  OF  THE  BRAIN 

in  a  series  of  combinations  and  creations  which  are  unconsciously  produced 
by  a  process  intimately  bound  up  with  cerebral  activity,  animated  by  the 
theme  that  is  detained  in  the  focal  point  of  consciousness. 

It  is  of  capital  importance  in  the  study  of  thought  to  recognise  the  innate 
creative  tendency  of  the  human  intellect.  As  already  remarked,  nature 
furnishes  only  the  raw  material  with  which  it,  or,  rather,  the  brain,  con- 
structs the  modest  products  of  the  simple  image  or  the  marvellous  and 
immortal  creations  of  genius.  In  like  fashion,  with  other  material,  man 
constructs  a  hut  if  he  be  a  savage,  a  modest  house  if  he  be  a  poor  labourer, 
or  a  sumptuous  palace  if  he  be  wealthy  ;  and  so  there  arise  the  small  hamlets 
and  the  great  metropolitan  cities  where  men  live,  associate  together,  vie  with 
one  another,  form  groups,  are  active  or  inert,  grow  and  die. 

In  the  evolution  of  thought  there  is  a  constant  process  of  construction  and 
interchange.  Notions  and  judgments  assume  different  forms,  and  thoughts, 
variedly  coloured  and  associated,  succeed  one  another  in  the  most  diverse 
combinations,  with  a  tendency  to  become  manifest  by  translating  themselves 
into  different  forms  of  movement,  which,  again,  vary  with  altering  conditions 
of  time  and  place.  Whilst  groups  of  ideas  are  being  formed  and  organised, 
components  of  one  pass  into  another  and  yet  another,  the  number  of 
combinations  being  greater  the  more  simple  they  are. 

In  the  image  of  "  paper,"  e.g.,  we  find  some  components  such  as  that  of 
the  white  colour  and  the  tacto-muscular  components  of  thinness,  pliability  and 
lightness,  which  belong  to  many  other  objects.  The  acoustic  image  of  paper, 
as  when  a  leaf  is  torn  from  a  book,  is  more  characteristic,  associated,  it  may  be, 
with  collateral  images  of  an  ink-bottle,  a  pen,  with  the  muscular  images  of 
writing  and  many  others.  All  these  images  are  likewise  to  be  found  as 
components  of  ever  so  many  other  psychic  complexes.  It  is  the  particular 
way  in  which  they  are  combined,  so  as  to  confer  specificity  upon  a  concrete 
image,  that  characterises  the  selective  power  of  the  brain  in  fixing  objective 
realities.  It  is  the  same  thing  with  oxygen,  carbon,  nitrogen,  etc.  ;  those 
elements  enter,  in  diverse  combinations,  into  an  incalculable  number  of 
organic  and  inorganic  compounds. 

In  the  fact  that  simple  images  form  components  of  a  large  number  of 
concrete  images,  and  that  their  combinations  may  be  multiplied  ad  infinitum, 
we  recognise  the  sovereignty  of  the  law  of  creation  and  evolution.  Every 
hour,  every  day,  man  receives  new  impressions  with  which  he  forms  new 
percepts.  These  enter  into  combination  with  pre-existing  percepts  and 
increase  thought,  which  always  reflects  reality.  Mental  constructions  which 
have  no  counterpart  in  reality,  and  give  no  indication  of  verisimilitude  or 
analogy,  belong  to  the  realm  of  pathology  or  its  borderlands. 

With  increase  of  the  psychic  products  resulting  from  continuous  action  of 
agents  of  nature  upon  the  perceptive  centres  (a  point  upon  which  psycholo- 
gists and  even  histologists  like  R.  y.  Cajal  are  agreed),  and  with  growth  of  the 
psychic  personality,  the  differentiation  of  the  ego  from  surrounding  nature 
becomes  more  decisive.  The  greater  the  number  of  percepts,  the  more  active 


INTELLIGENCE  AND  LANGUAGE  217 

the  process  of  assimilation  and  fusion  of  these  for  the  formation  of  more 
complex  psychic  products  reflecting  the  reality  of  the  physical  and  social 
environment,  and  the  more  complicated  and  diverse  the  reaction  on  the  cosmic 
and  social  environment,  the  more  distinct  becomes  the  ego  in  the  world 
in  which  it  lives  and  expands,,  because  the  more  intense  and  varied  is  its 
experience. 

The  psychic  products  formed  with  the  percepts  are  of  two  orders — 
aggregates  and  compounds.  The  former  can  be  decomposed  into  elements 
which  are  associated  with  each  other  in  a  most  varied  manner,  giving  rise  to 
different  representations.  The  latter  are  also  susceptible  of  analysis,  but  are 
more  stable,  for  they  represent  definite  external  facts  and  determined  rela- 
tions, associated  with  one  another  and  with  aggregates  in  the  most  varied 
manner,  in  the  perennial  motion  of  thought,  yet  conserving  an  always 
recognisable  individuality. 

All  the  concrete  images,  and  the  words  which  symbolise  them,  are  stable 
compounds,  inasmuch  as  they  express  real  objects  and  fixed  relations.  The 
concrete  image,  e.g.,  of  A  BOOK,  results  from  a  certain  number  of  more  ele- 
mentary images  now  fused  with  one  another  so  that  the  product  is  unalter- 
able. This  image  is  a  whole,  the  components  of  which  are  inseparable  from 
the  concrete  image  of  that  particular  book.  Books,  however,  differ  in  many 
particulars,  and  the  various  images  are  so  blended  as  to  give  rise  to  a  very 
variable  and  unstable  ideative  compound  which  is  the  general  idea  of  BOOK, 
quite  different  from  the  concrete  image  of  each  book.  The  latter  refers  to  a 
particular  book  which  I  have  seen  and  which  has  passed  through  my  hands, 
an  image  which  is  invariable  and  not  decomposable. 

The  general  idea  does  not  refer  to  any  concrete  image  but  to  a  conglomera- 
tion of  all  the  images  which  participate  in  it,  these  being  synthetised  in  the 
word  in  which  the  general  idea  is  moulded.  All  the  concrete  images  from 
which  the  general  idea  results  either  remain  on  the  first  level  of  consciousness 
(in  the  subconscious)  in  greater  or  less  number,  and  perhaps  on  its  threshold, 
indefinite  and  indescribable,  or  they  are  represented  in  consciousness,  more 
especially  those  which  memory  serves  up  because  they  are  more  definite  and 
more  coloured,  having  been  given  by  stronger  impressions,  and  because  they 
have  assumed  a  greater  number  of  associative  relations  and  are  therefore 
more  capable  of  forcing  the  threshold  of  consciousness.  The  general  idea 
becomes  stable  in  the  word  which  symbolises  it. 

If  a  man  forget  the  word  "  book  "  he  may  yet  be  able  to  picture  to  him- 
self single  books,  the  images  of  which  are  stable,  but  he  no  longer  possesses 
the  general  idea  of  BOOK. 

Concrete  images,  like  general  ideas,  have  a  strong  assimilative  power 
which,  in  a  manner,  is  proportionate  to  the  perceptive  and  attentive  capacity 
of  the  individual.  The  concrete  image  which  the  illiterate  or  poorly  educated 
man  holds  of  a  book  he  has  seen  is  very  different  from  that  which  the  studious 
man  has  of  each  volume  in  his  library.  A  much  smaller  number  of  com* 
ponents  enters  into  the  construction  of  concrete  images  formed  by  a  weak  or 
undeveloped  brain.  Not  only  so,  but  ill-developed  brains  are  incapable  of 


218  THE  MECHANISM  OF  THE  BRAIN 

constructing  general  ideas.  Their  poor  activity  stops  at  the  formation  of 
concrete  images,  and  even  these  are  made  up  of  a  scanty  number  of  com- 
ponents. The  construction  of  general  ideas  falls  within  the  capacity  of 
evolved  brains  alone.  The  assimilative  power  of  these  is  such  that  every 
image  or  psychic  complex  is  constantly  becoming  fuller  and  more  complete 
by  the  incorporation  of  assimilable  elements  of  the  external  world. 

The  general  idea  assimilates  the  new  images,  becoming  enlarged  and  more 
complex.  This  fusion  is  only  realisable  with  the  intervention  of  speech.  It  is 
the  word  which  possesses  the  summarising  and  synthetic  property  ;  it  is  like 
a  cold  matrass  into  which  there  fall,  like  distilled  drops,  new  images  which, 
throughout  the  course  of  life,  become  combined  with  pre-existing  images,  in 
accordance  with  the  apprehensive  capacity  of  the  personality.  The  word, 
that  small  and  inextensible  organism,  comprises  and  expresses  them  all  as 
one.  Thus  are  formed  concepts  which,  under  normal  conditions,  are  insep- 
arable from  names.  Conceptualism  and  nominalism  are  two  correlative 
terms  co-existent  with  two  indivisible  facts,  just  as  life  and  organism  are 
indivisible.  Life  may  cease  and  the  mummy  remain,  just  as  sometimes  the 
cenceptual  content  disappears  whilst  its  corpse,  the  word,  remains  ;  or,  again, 
the  form  may  be  moulded  without  life  and  without  content  by  the  inferior 
man,  like  the  paper  doll  made  by  the  infant.  The  live  concept  or  the  general 
idea  exists  only  through  the  word.  If  this  be  suppressed,  the  concrete 
images  of  each  book  may  remain,  but  no  longer  the  abstract  idea  of  BOOK. 

Images,  even  though  they  have  no  immediate  relations  with  time,  trans- 
port us  beyond  the  confines  of  the  immediate  circumstances  owing  to  their 
associative  bonds  and  to  the  fact  that  they  themselves  succeed  one  another 
in  time.  This  excursion,  in  consciousness,  beyond  immediate  and  direct 
perception  facilitates  immensely  the  expansion  of  consciousness  in  its 
relations  with  time  and  space  (memory  and  imagination). 

The  concrete  images  which  enter  into  the  structure  of  concepts  are  only 
duplicates.  They  have  no  life  of  their  own,  but  are  maintained  active  by 
their  centres  of  formation.  If  a  particular  formative  centre  is  destroyed  the 
concepts  lose  their  vitality  and  die,  because  they  come  to  lack  a  particular 
category  of  components.  Similarly,  the  concrete  images  of  individual 
objects  are  kept  active  by  the  elementary  images  from  which  they  result,  and 
the  more  complex  products  of  the  mind  by  the  latent  life  of  all  the  mnemonic 
traces  from  which  they  are  formed  and  which  remain  behind  the  threshold 
of  consciousness.  The  clinique  provides  us  with  numerous  examples  in 
illustration. 

Cerebral  activity  is  conditioned  precisely  by  the  continuous  flow  of 
specific  waves  (images)  from  all  parts  of  the  cerebral  mantle. 

Every  nascent  thought  is  sustained  by  the  whole  train  of  images  which, 
through  their  associative  relations,  go  to  compose  it. 

The  whole  history  of  destructive  foci  in  the  sensory  centres,  the  evolu- 
tionary zones  (language)  and  the  associative  paths,  is  a  complete  and  irre- 
fragible  demonstration  of  this  law,  which  animates  and  governs  all  the 
complicated  mechanism  of  the  intellect.  If  one  cortical  area  is  destroyed,  or 


INTELLIGENCE  AND  LANGUAGE  219 

a  path  of  communication  intercepted,  the  activity  of  all  the  other  mental 
fields  is  diminished  and  the  whole  intellectual  life  feels  the  effect. 

In  the  constant  movement  of  images  the  prevailing  tone  comes  from  those 
which  have  a  predominance  over  the  others,  because  of  their  number  and 
representative  vividness.  So  it  happens  that,  in  the  movement  and  ex- 
trinsication  of  thought,  some  men  appear  more  visual,  if  the  visual  images 
prevail  over  the  others,  whilst  others  are  more  auditory,  or  more  conceptual 
or  more  sensory,  according  to  individual  circumstances. 

In  no  case  can  it  ever  be  said  that  only  one  single  form  of  memory  comes 
into  play.  The  motor  memory  of  singers,  the  visual  memory  of  painters,  or 
the  auditory  memory  of  musicians  is  always  associated  with  all  the  other 
memories.  What  we  have  to  deal  with  here  is  a  predominance  of  one  form 
over  others.  If  certain  writers  are  so  constituted  in  mind  that  their  auditory 
images  have  the  predominance,  so  that  in  reading  their  productions  we  are 
struck  by  the  rhythm  and  harmony  of  their  phrases,  whilst  in  others  there  is 
a  prevalence  of  visual  images  so  that  colours,  in  all  their  shades,  spring 
before  our  mind's  eye  in  the  most  harmonious  pictures,  yet,  in  every  case  the 
product  is  still  a  complex  one. 

The  history  of  art  teaches  us  that  many  artists,  visuo -motor  or  auditory- 
motor,  are  more  sensory  than  conceptual,  just  as  youth  is  more  sensory  than 
mature  age,  and  the  childhood  of  the  race  more  so  than  succeeding  genera- 
tions who  have  advanced  in  thought  and  action.  Conceptualism  predomin- 
ates in  maturity  and  in  a  very  advanced  civilisation,  but  art,  which  precedes 
science  and  history,  is  transformed  later  into  historical  and  conceptual  art, 
responding  to  the  influence  of  progress  in  the  order  of  knowing  and  feeling. 


* 
*  * 


From  all  the  foregoing,  it  seems  clear  that  the  whole  mental  edifice  rests 
upon  the  law  of  association.  Aggregations  and  combinations  (the  "  fusion  " 
of  Wundt)  are  not  possible  except  through  the  associative  power  of  all  the 
psychic  formations,  from  the  simplest  to  the  most  complex,  and  through 
the  anatomical  substratum  which  supplies  the  organic  and  mechanical  con- 
ditions necessary  to  the  psychic  dynamism,  regarded  in  the  manner  already 
indicated. 

Association  consists  in  the  connections  that  are  established  between 
ideas,  emotions  (Scripture)  and  movements.  These  connections  are  formed 
between  all  the  images  corresponding  to  objects  external  to  ourselves  (James), 
between  the  complexes  that  arise  from  combinations  of  these  same  images 
and  between  all  the  forms  of  reactions  of  the  self.  In  this  mechanism  lie  the 
germ  and  substance  of  logic. 

Two  forms  of  association  are  generally  spoken  of :  (1)  associations 
founded  on  resemblance,  and  (2)  associations  founded  on  contiguity,  or, 
according  to  Wundt,  (a)  intrinsic,  and  (6)  extrinsic  associations.  Intrinsic 
associations  correspond  to  those  founded  on  resemblance ;  extrinsic  to  those 
dependent  upon  contiguity.  If  the  physiognomy  of  one  person  resembles 
that  of  another  whom  1  know,  so  that  a  chance  meeting  with  the  first  at  once 


220  THE  MECHANISM  OF  THE  BRAIN 

calls  up  the  image  of  the  second,  in  this  case  the  bonds  of  association  are 
close,  some  elements  of  the  two  personalities  coincide  and  the  association 
is  intrinsic.  If,  on  the  other  hand,  I  meet  a  person  whom  I  have  seen  on  a 
former  occasion  in  some  other  place,  so  that  I  now  picture  to  myself  that 
locality  or  the  image  of  another  person  who  happened  also  to  be  there,  such 
an  association  between  person  and  place,  or  between  two  unlike  persons  and 
the  place  where  they  were  at  the  same  time,  and  consequently  between  the 
respective  images,  is  extrinsic,  because  here  we  have  to  deal  only  with  a 
coincidence  which  does  not  touch  the  nature  or  the  form  of  the  objects. 

Associations  are  also  divided  by  certain  psychologists  (Wundt,  Kraepelin, 
Aschaffenburg)  into  two  great  classes  :  immediate  and  mediate  associations. 
The  latter  are  produced  through  the  medium  of  a  common  term  without  this 
term  itself  appearing  in  consciousness.  Language  offers  a  good  field  for 
experiment.  Immediate  associations  are  divided  into  two  groups,  according 
as  the  word  pronounced  is  understood,  or  merely  evokes  an  association 
through  its  quality  of  a  simple  sound.  When  the  word  is  understood,  we  get 
co-ordinative  and  subordinative  associations.  The  word  "statute/'  e.g.,  calls 
up  the  word  "law,"  "asylum"  suggests  "madness,"  "nightingale"  sug- 
gests "  bird  "  ;  or  the  relation  of  the  associated  words  may  be  predicative, 
as  in  "  ripe-fruit,"  "  black-ink,"  or  causal,  as  in  "  merit-decoration," 
"  alcohol-drunkenness  "  ;  these  are  internal  associations.  Associations  due 
to  assonance  (rhyme)  enter  into  another  group.  Bourdon  distinguishes 
four  forms  of  verbal  associations,  but  it  is  needless  to  enter  into  details. 

External  are  more  frequent  than  internal  associations  (Aschaffenburg) 
and  at  the  same  time  more  rapid.  Those  of  nouns  are  greatly  in  excess  of 
those  of  verbs. 

In  the  case  of  associations  due  to  co-ordination  and  subordination  we 
have  quality  associated  with  object  and  object  with  quality.  Similarly, 
in  another  field,  one  letter  is  associated  with  another  letter,  a  word  with  a 
letter,  the  name  of  a  colour  with  a  letter,  one  word  with  another  word,  a 
number  with  a  colour  (Calkins) . 

In  some  men  co-ordinate  associations  prevail,  others  again  associate 
more  frequently  and  easily  through  subordination.  This  explains  to  some 
extent  the  diversity  in  syntactical  forms  of  speech.  It  is  the  particular 
nature  of  the  associations  that  impresses  a  particular  character  on  the 
intellect ;  for  instance,  the  intellect  of  the  reasoner  differs  from  that  of 
the  descriptive  writer,  owing  to  a  relative  homogeneity  of  the  mind  of  the 
reasoner,  compared  with  that  of  the  descriptive  writer  (Bourdon). 

Associations  due  to  contrast  are  among  the  most  frequent  and  most 
active  in  the  process  of  thought,  and  they  furnish  the  most  plausible  ex- 
planations of  an  infinity  of  normal  and  morbid  phenomena  which  would 
otherwise  remain  quite  obscure.  In  some  intellectual  and  affective  categories 
the  first  and  last  components  of  the  series  are  more  closely  associated  than 
all  the  intermediate  components. 

In  the  field  of  sensation  white  is  more  closely  connected  with  black  than 
with  the  intermediate  shades  of  grey  ;  the  image  of  the  heaviest  body 


INTELLIGENCE  AND  LANGUAGE  221 

is  closely   associated   with   that  of   the  lightest  body  ;    representation   of 
smoothness  is  associated  with  that  of  roughness,  etc. 

In  the  domain  of  feelings,  pleasure  and  pain  come  together,  although  they 
are  the  extremes  of  a  series  of  gradations  of  pleasures,  pains  and  indifferent 
sensations.  Friendship  supposes  enmity,  love  supposes  hatred,  fear  supposes 
courage,  and  so  on ;  as  we  mount  in  the  scale,  the  beautiful  supposes  the 
ugly,  the  moral  the  immoral,  the  perfect  the  imperfect,  the  wholesome 
the  unwholesome,  the  illiterate  the  cultured. 

Many  such  contrasts  are  the  negative  side  of  an  affirmation.  When  we 
judge  men  to  be  good,  moral,  beautiful,  cultured  or  disciplined  we  at  the 
same  time  formulate  comparative  judgments,  and  we  represent  to  ourselves 
bad,  immoral,  ugly,  uncultured,  undisciplined  men,  whose  images  are  very 
closely  associated  with  those  of  the  others,  so  closely,  indeed,  that  whenever 
I  summon  up  any  one  of  either  series  the  contrasting  correlative  of  the 
opposite  series  is  immediately  evoked. 

The  law  is  that  associations  due  to  maximum  differences  are  stronger 
than  those  founded  upon  resemblance  or  minimum  differences. 

Contrasts  become  established  from  the  earliest  appearance  of  mental 
associations,  side  by  side  with  associations  due  to  resemblance  and  con- 
tiguity. When  an  infant  stretches  out  his  little  hand  towards  a  burning  light 
(tropism  ?)  and  feels  the  pain  of  the  burn,  he  notes  and  remembers  the  contrast 
between  the  pleasant  aspect  of  the  bright  light  and  the  pain  that  results 
from  contact  with  it.  If,  in  order  to  wean  her  child,  a  mother  puts  some 
bitter  solution  on  the  nipple,  there  arises  a  strong  association  of  contrast 
between  the  pleasure  of  sucking  and  the  repellent  bitterness  of  the  nipple. 
The  smile  that  inspires  the  playful  attitude  of  a  father  towards  his  infant 
becomes  associated  with  the  crossness  that  determines  the  father's  severe 
behaviour. 

A  great  part  of  the  education  of  infants  rests  upon  the  law  of  psychic 
contrast.  Aspirations,  desires,  movements,  that  are  opposed  and  hindered, 
associated  as  they  are  with  opposite  trends  of  mind  with  their  correlative 
ideas,  furnish  very  numerous  examples  of  association  by  contrast.  Love 
and  hate,  confidence  and  diffidence,  courage  and  fear,  are  the  emotions  most 
frequently  alternating  in  consciousness,  being  ever  in  contact,  as  it  were, 
on  its  threshold.  Dumas,  unlike  many  psychologists  who  either  make  no 
mention  of  psychic  contrast  or  deny  it  altogether,  wrote  :  "  Man  is  a  very 
strange  animal,  wholly  made  up  of  contrasts."  After  Bain  no  others  have 
illustrated  the  importance  of  the  phenomena  of  contrast  in  the  succession 
and  association  of  ideas,  emotions  and  actions,  more  fully  than  Paulham 
and  S.  di  Sanctis.  G.  Bruno,1  however,  had  previously  recognised  the  law 
of  psychic  contrast,  maintaining  "  that  the  beginning,  middle  and  end,  tne 
birth  and  the  perfection  of  all  we  see,  arises  from  contraries,  through 
contraries,  in  contraries." 

The  intense  love  that  the  neuropathic  mother  has  for  her  child  awakens 
in  her  consciousness  the  fear  that  some  illness  may  carry  off  the  infant,  in 

1  G.  Bruno.     "  Pensieri."     Raccolia  di  Sreviari  iniellettuali. 


222  THE  MECHANISM  OF  THE  BRAIN 

contrast  with  the  joy  of  possession  ;  or  it  may  be  that  when  she  leans  upon 
a  balcony  she  fears  that  she  will  cast  down  the  object  of  her  love.  A  great 
number  of  psychic  disturbances  are  to  be  interpreted  solely  through  associa- 
tions due  to  contrast,  and  instances  of  delusions  and  obsessions  due  to  contrast 
are  more  frequent  than  is  generally  believed. 

As  far  back  as  1886,  in  a  study  of  psychic  polarisation,1  the  writer  set 
forth  clearly  the  principle  of  association  due  to  contrast.  "  This  fundamental 
logical  process,"  he  then  wrote,  "  is  the  resultant  of  the  associative  relations 
of  sensations  and  ideas,  especially  relations  of  antithesis,  with  which  are 
associated  analogous  states  of  pleasure  and  pain.  Hence  it  comes  about 
that  in  the  process  of  arriving  at  a  conclusion,  in  normal  mental  functioning, 
every  idea  bears  with  it  the  antithetical  idea  ;  only,  it  happens  that,  owing 
to  the  directing  attention,  the  antithetical  idea  does  not  reach  the  focal 
point  of  consciousness  but  remains  hidden,  though  not  inactive,  in  the 
unconscious." 

Even  to-day,  after  many  years,  the  author  is  still  of  opinion  that  this 
idea  serves  as  a  useful  interpretation.  The  whole  doctrine  of  Freud  is 
supported  by  this  fundamental  law. 

When  an  individual  proposes  to  himself  to  do  something,  ideas  more  or 
less  actively  in  contrast  with  this  soon  present  themselves  to  his  consciousness. 
The  detailed  descriptions  of  mental  phenomena  given  by  Socrates,  and 
attributed  to  his  "  daimon  "  (Lelut),  were  nothing  more  nor  less  than  pheno- 
mena of  psychic  contrast.  The  same  thing  may  be  said  of  the  motives  and 
counter-motives  that  dispute  with  one  another,  in  the  field  of  consciousness, 
the  government  of  our  actions. 

Every  neuro-pathologist  has  experience  of  individuals,  more  especially 
hysterical  subjects  and  neuropathic  children,  who  act  contrary  to  the  in- 
junction or  the  recommendation  given  them.  Some  people,  when  they  wish 
to  avoid  disturbing  their  neighbours  by  sneezing  or  yawning,  feel  compelled 
to  yawn  or  sneeze  (contrast  arising  from  inhibition) . 

The  anxious  fear  of  committing  some  act  that  is  dangerous  or  repugnant 
to  the  conscience  drives  into  the  field  of  consciousness  all  the  images  con- 
nected with  that  act ;  and  these  images,  especially  in  degenerates,  are 
endowed  with  an  extraordinary  impulsive  activity.  Therein  lies  the  explana- 
tion of  the  fact  that  those  who  are  greatly  afraid  of  death,  and  especially  of 
suicide,  end  by  committing  suicide  (coercion  due  to  contrast).  Religious 
practices  and  the  vow  of  chastity  often  excite  intensely  erotic  ideas  and 
desires.  The  hysterical  eroticism  which  claimed  so  many  victims,  even 
in  the  monasteries,  in  the  Middle  Ages,  was  the  effect  of  contrast  between 
the  desire  that  arose  from  the  over- excited  organic  needs  and  the  ideas 
of  chastity  which  the  numerous  monastic  orders  and  sects  attempted 
to  inculcate  in  mankind,2  in  the  belief  that  chastity  represented  the  highest 
virtue. 

1  Bianchi.     "  Archivio  di  Psichiatria,  Scienze  Penali  e  Antr.  Grim."  and  Revue 
Philosophique.     1886. 

2  Bianchi.     "  II  nervosismo  di  quosta  fine  di  secolo."     Flegrea.     Naples,  1899. 


INTELLIGENCE  AND  LANGUAGE  223 

This  contrast  is  depicted  in  one  of  the  most  celebrated  paintings  of 
Morelli  (The  Temptations  of  Saint  Anthony). 

Some  people  who  have  dedicated  themselves  to  religious  practices  become 
tormented  by  lascivious  images,  because  chastity  forms  the  one  aim  of  their 
conduct.  Cases  of  this  kind  have  been  reported  by  Lemesle. 

Many  delusions  are  hinged  upon  association  due  to  contrast.  Here, 
again,  we  have  an  illuminating  example  of  the  fact  that  our  knowledge  of 
the  phenomena  of  normal  psychology  and  of  the  laws  regulating  healthy 
mental  life  can  be  completed  by  analysis  of  pathological  facts. 

Associations  may  undergo  a  species  of  interference,  an  analogy,  applied 
rather  inaccurately,  if  we  adhere  to  the  strictly  physical  sense  of  the  term, 
by  A.  Bergstrom.1  Interference  of  associations,  says  this  author,  is  a  funda- 
mental fact  of  the  nervous  system  and  consists  in  this,  that  once  an  association 
is  established  between  two  terms,  A  and  B,  any  new  association  that  we 
attempt  to  set  up  between  A  and  C  comes  into  conflict  with  the  former. 
In  general,  when  we  wish  to  exchange  a  customary  mode  of  doing  a  thing 
for  another  mode  the  old  habit  resists,  and  when  we  are  wearied  or  busied 
with  some  other  matter  the  tendency  is  to  revert  to  the  old  fashion.  The 
law  of  interference  is  just  as  fundamental  as  that  of  habit,  which  has  been 
interpreted  in  a  masterly  manner  by  James.  The  reason  why  we  are  not 
inclined  towards  anything  that  is  new  lies  in  the  fact  that  we  are  not  inclined 
to  make  the  effort  required  for  new  associations.  This  is  referable  to  another 
law  of  life — the  law  of  least  resistance  or  the  law  of  misoneism.  Bergstrom's 
experiments  are  directly  intended  to  prove  the  fact  that,  notwithstanding 
every  effort,  a  decided  interference  takes  place  when  we  endeavour  to  associate 
a  new  reaction  with  an  old  stimulus,  just  as  when  something  is  learned  in  a 
new  or  different  fashion.  The  confusion,  writes  Bergstrom,  that  we  find  in 
the  mind  of  young  students  when  an  argument  is  presented  to  them  in 
a  different  form  is  a  case  in  point.  Much  of  what  has  been  attributed  to 
failure  of  memory  in  advanced  age  ought  to  be  placed  in  the  category  of 
interferences. 

The  creative  imagination,  however,  is  not  specially  regulated  by  any  of 
.the  known  laws  of  association,  nor  does  it  always  require  a  clear  memory 
with  a  considerable  wealth  of  sensible  representations  to  serve  all  its  com- 
binations. In  it  there  come  into  play  the  elements  of  chance  and  logical 
incoherence  ( Vaschide 2) .  According  to  this  acute  observer  the  first  dreams 
of  young  children,  like  the  fibs  they  tell,  are  phenomena  of  creative  imagina- 
tion, based  on  the  lack  of  precise  perception  of  the  real  facts  and  on  error 
of  the  senses. 

Who  can  tell  under  how  many  different  aspects  things  may  be  regarded  ? 
How  different  are  the  judgments  pronounced  upon  things  that  closely  resemble 
one  another  !  If  little  drops  of  ink  are  allowed  to  fall  on  pieces  of  cardboard 
and  we  press  other  pieces  of  cardboard  upon  these,  the  ink  squeezed  out  will 

1  Bergstrom.     "  Experiments  upon  Physiological  Memory  by  Means  of  Inter- 
ference of  Associations."     Amer.  Journ.  of  PsychoL     1892-1893. 

2  Vaschide.     La  logique  morbide*     1902. 


224  THE  MECHANISM  OF  THE  BRAIN 

make  spots  of  various  shapes.  In  such  spots  one  child  will  see  a  horse, 
another  child  an  animal  with  its  mouth  open,  whilst  another  will  find  there 
the  head  of  his  teacher  or  his  teacher's  wife,  all  of  them  noting  the  strangest 
resemblances.  This  is  not  a  case  of  illusion,  but  of  association  due  to  likeness 
or  analogy  of  these  objective  figures  with  others  that  are  preformed  and  very 
readily  reproducible  in  memory.1 

Protracted  mental  work  exercises  a  notable  influence  on  the  associative 
power  and  on  the  quality  of  the  associations.  With  the  onset  of  fatigue, 
the  number  of  internal  associations  diminishes  considerably,  whilst  the 
number  of  external  associations,  such  as  those  formed  between  rhymes  or 
sounds  of  words,  increases  as  the  work  proceeds.2  This  phenomenon  should 
have  a  very  great  significance  for  pedagogues  and  compilers  of  scholastic 
programmes. 

«/ 

If  the  author  has  dwelt  upon  the  subject  of  the  associations  longer  than 
may  seem  necessary,  it  has  been  with  the  object  of  furnishing  proof,  from  this 
additional  source,  that  every  sensation  provoked  by  the  external  world,  as 
it  excites  one  sense  or  several  senses  together  and  crosses  the  threshold  of 
consciousness,  induces  an  extensive  movement  of  cerebration.  The  work  of 
perception  and  judgment  never  remains  circumscribed  within  the  cortical 
field  of  the  sense  excited,  but,  through  the  fibres,  the  neurofibrils  of  the 
dendrites  and  of  the  axis-cylinder  prolongation  of  each  cell,  by  direct  and 
indirect  paths,  it  provokes  a  great  amount  of  work,  more  or  less  intense, 
which  involves  the  whole  cerebral  mantle,  or  a  great  part  of  it,  according  to 
the  degree  of  development  and  culture  of  the  individual. 

Association  between  ideas  has  a  bearing  upon  the  formation  of  pro- 
positions, which  include  a  judgment  or  a  conclusion  on  the  relations  of  two 
or  more  of  these  associations.  Every  proposition  contains  the  elements  of 
conviction,  in  so  far  as  every  conclusive  judgment  tends  to  affirm  or  to  deny. 

Reasoning,  which  is  essentially  made  up  of  propositions,  is  nothing  else 
than  a  more  extensive  and  complex  association  of  propositions,  the  associated 
components  of  which  possess  correlatives  of  time,  place  and  number,  from 
which  arise  the  grammatical  inflexions  of  words  and  the  syntactical  form, 
these  being  the  product  of  a  more  advanced  mental  evolution. 

Only  a  part  of  the  mental  capital  of  each  man  can  be  represented  in 
consciousness,  and  that  under  specially  determined  circumstances  and  always 
according  to  the  laws  of  association.  Only  a  small  number  of  representa- 
tions can  be  brought  together  in  the  focal  point  of  consciousness  or  even 
within  its  visual  field,  in  a  given  unit  of  time  (determined  by  Wundt)  ; 
all  the  rest  constitutes  what  we  term  the  unconscious  (or  the  subconscious), 
which  furnishes  all  the  elements  necessary  for  the  development  of  a  particular 

1  Dearborn.     A  Study  of  Imagination.     Amer.  Journ.  of  Psychol.     1901. 

2  Richerche  di   Aschaffenbiirg   e   di   Binet   e   Henry.     La  Jatigue   intellectuelle. 
Paris,  1898. 


INTELLIGENCE  AND  LANGUAGE  225 

thought  or  a  particular  line  of  conduct.  It  is  evident  that  this  development 
will  be  more  or  less  felicitous  (1)  according  as  the  unconscious  holds  a  larger  or 
smaller  stock  of  cognitions  ;  (2)  as  its  constituent  elements  are  well  connected 
with  one  another  ;  (3)  as  the  nerve- cells,  perfectly  sound  and  active,  furnish 
their  memory-traces  punctually  and  faithfully  ;  (4)  as  the  innumerable 
associative  paths  (fibres  and  neurofibrils)  are  pervious  so  as  to  permit  the 
reawakening  of  the  correlative  mnemonic  traces  even  in  the  deepest  recesses 
of  oblivion,  according  to  the  laws  of  association  ;  (5)  according  to  the  extent 
to  which  all  this  material  is  offered  to  the  creative  power  of  the  intellect. 

The  whole  mental  content  may  cross  the  focal  point  of  consciousness 
according  to  the  laws  of  succession  and  connection  (the  law  of  succession  may 
be  included  with  that  of  time  in  the  psychic  processes,  and  the  law  of  con- 
nection with  that  of  space,  which  is  another  condition  affecting  associations) . 

In  the  unconscious  lie  both  the  debris  of  mind  and  the  elements  of  genius ; 
there  the  former  may  ferment  and  conspire,  eventually  forcing  the  threshold 
of  consciousness  ;  there,  too,  the  latter  may  sparkle  with  unexpected  light, 
beaming  forth  to  illuminate  new  paths  of  life. 

Considerable  importance  attaches  to  the  former  elements,  those  psychic 
complexes  or  constellations  which  sometimes  conspire  in  the  unconscious, 
(Freud)  and  determine  particular  emotional  states. 

The  whole  capital  of  sensory  images  contributes  to  the  formation  of  the 
various  categories  in  the  development  of  thought.  The  categories  are  of 
diverse  evolutionary  grade  according  to  their  content  of  thought  and  senti- 
ment. From  all  that  has  gone  before,  it  seems  clear  that  in  our  examination 
of  intelligence  we  should  inquire  into  the  quantity  and  complexity  of  the  ideas 
(whether  simple  or  compound),  their  re-evocation,  their  associations  and 
combinations,  the  capacity  of  the  brain  to  make  use  of  the  thought- content 
of  the  social  environment  (judgments,  beliefs),  all  this  being  reconstructed 
into  language  and  resolved  into  conduct.  Thus,  the  scientific  conception 
of  the  mechanism  of  intelligence  here  put  forward  is  inseparably  connected 
with  that  of  language  in  its  more  evolved  extrinsications. 

Language  made  its  appearance  as  an  emotional  reflex,  and  has  attained 
the  highest  rank  amongst  the  cerebral  functions,  whilst  at  the  same  time  its 
mechanism  has  become  gradually  more  complicated.  The  study  of  language 
embraces  a  large  part  of  the  difficult  problem  that  concerns  the  mechanism 
of  the  cerebral  functions.  The  functional  complication  and  the  high  psychic 
value  it  has  attained  had  not  been  possible  were  it  not  for  the  specific  differen- 
tiation of  extensive  regions  of  the  cerebral  cortex.  Speech  is  the  product  of 
a  long  and  laborious  process  in  which  numerous  psycho -physiological  factors 
co-operate.  It  is  co-extensive  with  the  anatomical  basis.  Language  might 
be  said  to  be  an  organism  which  has  its  own  evolutionary  history,  closely 
bound  up  with  the  story  of  the  evolution  of  thought,  and  is  the  result  of 
many  diverse  constituent  elements  intimately  connected  with  one  another. 

The  law  of  evolution  is  here  apparent  as  the  supreme  law  of  thought  and 
of  language,  of  content  and  of  form.  The  development  of  speech  marks  the 
great  trajectory  described  by  human  thought,  detaching  man  from  all  other 


226  THE  MECHANISM  OF  THE  BRAIN 

animal  species,  in  the  comprehension  of  his  environment  and  of  all  nature. 
Just  as,  in  the  development '  of  organisms,  cells  become  multiplied  and 
differentiated  and  assume  different  forms,  so  human  language,  by  the  develop- 
ment of  thought  and  the  constant  differentiation  and  distinction  of  objects, 
qualities,  states  and  relations  has  become  constantly  enriched  with  new 
forms. 

Again,  just  as  in  the  embryonic  development  of  the  human  organism  some 
elementary  transitional  forms  disappear  to  give  place  to  elements  that  are 
more  stable  and  more  adapted  to  life,  in  the  struggle  with  external  agents, 
so  it  is  with  the  dead  languages  and  possibly  with  others  which  will  die,  in- 
sufficient as  they  were  or  are  for  the  purpose  of  their  existence  under  the 
new  conditions  of  intellectual  life  and  the  successive  states  of  society.  Just 
as  the  transitional  tissues  which  have  disappeared  never  again  return  to  life, 
so  the  dead  languages  became  dissipated  in  the  genesis  of  the  tongues  which 
came  after  them,  and  the  latter  in  those  which  presently  exist.1 

1  The  doctrine  that  language  was  revealed  to  man  by  a  Divine  Creator,  and  that 
the  first  human  beings  expressed  their  thoughts  and  emotions  in  well-formed  words, 
finds  no  acceptance  now  except  in  the  minds  of  theologians.  The  publications  of 
Grimm  and  Renan,  reviving  the  genial  intuitions  of  Lucretius,  have  met  with  wide 
approval. 

That  language  has  an  origin  and  an  evolutionary  history  inseparable  from  that 
of  thought  is  a  hypothesis  generally  accepted  to-day  not  only  by  naturalists, 
particularly  as  the  result  of  the  diffusion  of  the  Darwinian  doctrines,  but  also  by 
philologists  and  glottologists.  Their  wonderful  investigations  have  laid  bare  a 
long  retrospective  history  buried  under  the  upper  layers  of  modern  tongues,  just  as 
the  geologist  draws  his  deductions  regarding  the  successive  formations  and  the 
great  cataclysms  which  transformed  the  crust  of  the  earth  which  we  inhabit  from 
the  superimposition  of  strata  of  which  the  earth  is  formed  and  from  the  traces  of 
petrified  beings  who  lived  in  other  times. 

To  biologists,  and  even  to  the  generality  of  philologists,  the  question  whether 
language  has  had  one  origin  only,  or  several  origins  in  different  regions  of  the  earth 
far  distant  from  one  another,  is  a  matter  of  minor  importance.  In  either  case  the 
primitive  tongues  must  have  arisen  by  branchings  off  (as  the  result  of  the  inter- 
vention of  a  great  number  of  coefficients,  internal  and  external),  from  stems  or  roots 
which,  notwithstanding  their  simplicity,  contained  the  germs  of  the  luxurious 
filiation  of  modern  tongues,  just  as  seeds  contain  all  the  elements  of  the  new  growths 
that  arise  from  them.  Language  is  the  result  of  a  slow  evolution  that  had  its 
commencement  in  the  modulation  of  the  inarticulate  voice  of  beings  who  preceded 
primitive  man,  under  the  action  of  emotion-producing  stimuli. 

Leaving  aside  observations  on  animals,  we  can  start  out  with  the  certain  datum 
that  the  emotional  states  of  man  translate  themselves  into  movements  and  attitudes 
which  vary  with  changes  in  the  content  of  emotion.  Fear  and  courage,  love  and 
hatred,  pleasure  and  pain,  besides  the  appetites,  all  have  their  language,  inasmuch 
as  they  tend  to  be  converted  into  movements  :  they  induce  different  tones  in  the 
muscular  groups  of  the  face,  giving  rise  to  changes  in  physiognomy,  and  they  cause 
a  number  of  movements  of  the  trunk  and  limbs  which  in  combination  with  the 
foregoing  express  changing  states  of  mind.  The  emotional  language  of  man  finds 
its  counterpart  in  analogous  attitudes  of  the  higher  mammals.  Let  anyone  notice 
the  joy  of  a  hunting  dog  when  he  sees  his  master  put  on  his  hunting  suit,  or  the 
mortification  of  the  same  animal  when,  after  he  has  stolen  a  piece  of  meat,  he  finds 
himself  in  front  of  his  angry  master  and  crouches  down,  dejected  and  suspicious, 


INTELLIGENCE  AND  LANGUAGE  227 

Language,  expressing  as  it  does  emotions  and  ideas,  should  be  examined 
from  both  the  subjective  and  the  objective  sides.  Besides  conveying  our 
ideas,  it  has  the  property  of  reawakening  in  other  individuals  who  hear  us 
and  perceive  our  words  the  same  emotion  as  stirs  us.  Indeed,  there  is  good 
reason  to  believe  that  in  its  earliest  development  it  has  been  almost 
exclusively  emotional. 

and  let  him  compare  the  two  attitudes  of  the  dog  with  those  of  happy  urchins  who, 
on  a  fe*te-day,  strut  along  in  front  of  an  instrumental  band,  cutting  capers  all  the 
time,  or  with  that  of  a  mother  who  has  just  lost  a  loved  one,  then  he  can  testify  to 
the  mute  language  of  the  emotions,  as  these  may  be  read  in  physiognomy  and  in 
gesture. 

The  court  paid  by  the  male  to  the  female  cephalopod  in  an  aquarium,  the  agita- 
tion of  ants  when  their  own  nest  is  attacked  by  another  colony  which  has  exhausted 
its  provisions,  the  vigilant  and  suspicious  air  of  the  old  elephant  as  he  comes  out  of 
the  Avood  into  the  open  to  make  sure  that  no  danger  threatens  his  companions  when 
they  seek  the  pasture,  or  the  agitation  of  the  swallow  which  finds  its  nest  occupied 
by  an  insolent  sparrow,  all  prove  to  us  that  there  is  an  immediate  and  constant 
relation  between  emotions  and  movements  and  that  a  communication  of  these 
emotions  takes  place  between  individual  animals  forming  one  group.  It  is  certainly 
a  form  of  language.  To  feel  and  to  act  represent  two  terms  of  the  emotions  which 
man  incarnates  in  a  marvellous  number  of  physiognomic  expressions,  and  these  are 
the  first  phases  of  language. 

The  dominating  sentiment  in  each  individual  confers  a  prevalence  upon  the 
relative  muscular  attitudes,  and  a  trace  of  this  remains  which  does  not  escape  the 
trained  observer.  It  is  in  these  traces  that  we  read  the  mute  language  of  the  human 
heart ;  it  is  by  their  guidance  that  we  penetrate  into  its  recesses,  and  the  mind  is 
unconsciously  led  by  these  intuitions  into  the  tepid  or  warm  regions  of  sympathy, 
or  into  the  grey,  cold  and  repellent  regions  of  antipathy. 

Photographs  of  physiognomies  compose  a  very  interesting  ana  instructive  book 
on  the  language  of  the  human  heart.  In  it  there  are  certainly  enigmatic  pages,  but 
these  belong  to  the  icy,  the  torpid,  and  to  simulators,  including  certain  diplomats 
and  politicians  whose  spoken  words,  governed  by  strong  will  and  interest  to  be 
conserved,  serve  to  hide  their  real  thought  and  sentiment.  This  is  the  art  of  lying  ; 
it  is  the  exercise  of  will  over  the  muscles  of  the  physiognomy,  with  a  power  that 
these  cannot  escape. 

It  is  to  be  borne  in  mind  that  the  vocal  organs  and  buccal  nervous  centres  in  man 
are  very  highly  developed,  and  it  is,  therefore,  not  out  of  the  way  to  suppose  that 
strong  emotional  states,  besides  betraying  themselves  in  movements  of  the  face, 
limbs  and  body,  might  provoke  also  movements  of  the  vocal  organs,  combined 
with  movements  of  the  tongue  and  lips  ;  and  that  thus  were  formed,  in  ages  long 
gone  past,  the  first  articulate  sounds  of  primitive  man.  The  association  between 
the  object  and  the  phenomenon  provoked  by  the  emotion  in  the  form  of  an  articulate 
vocal  sound,  its  immediate  reflex,  indicates  the  symbolic  character  of  articulate 
sounds,  more  especially  because  the  same  phenomenon  would  be  induced  under 
similar  circumstances.  It  is  a  generally  accepted  opinion,  as  held  in  ancient  times 
by  Plato  (in  the  Cratile),  and  afterwards  by  Leibnitz  and  De  Brosses,  and  in  recent 
times  by  Renan,  Max  Miiller  and  other  philologists  and  naturalists,  that  language 
had  an  imitative  origin.  This  view  finds  support  in  the  fact  that  the  imitative 
reflex  is  very  commonly  found  where  intelligence  is  less  developed.  Children, 
savages  and  imbeciles  imitate  much  more  than  normally  developed  adults.  Again, 
when  consciousness  is  put  to  sleep  by  the  induction  of  hypnotic  states,  in  which 
individual  initiative  is  suppressed,  the  imitative  capacity  is  enormously  augmented. 

In  the  infancy  of  humanity,  imitation  reproduced  sounds  and  noises  in  articulate 


228  THE  MECHANISM  OF  THE  BKAIN 

Later  it  lias  become  more  cognitive,  inasmuch  as  its  content  is  much 
more  largely  made  up  of  notions. 

Simple  vowel  sounds,  and  even  mimicry  alone,  are  more  than  sufficient 
for  the  expression  of  elementary  emotional  states,  but  one  cannot  conceive 
the  possibility  of  transmitting  notions  to  others  except  with  the  aid  of  words, 
which  give  form  to  thoughts.  Emotional  language  always  remains  the  mode 

voices  which  were  simply  the  reflex  of  analogous  phenomena  which  struck  the 
senses.  The  running  of  water  with  its  sustained  sound  probably  provoked  in  a 
reflex  way  the  sound  of  r,  which  in  itself  indicates  movement.  This  syllabic  sound 
is  found  in  a  great  number  of  words  which  have  a  content  of  movement  accompanied 
by  more  or  less  noise.  Words  have  been  gradually  formed  by  the  addition  of 
aifixes  and  suffixes  ;  in  the  Italian  language  we  have  rumore,  rotolare,  ruggire, 
scorrere,  correre,  rifare,  tremare,  fremare,  which  preserve  the  motor  element  in  one 
form  or  another.  Breaking,  with  the  noise  it  produces,  becomes  expressed  by  the 
Sanscrit  rug,  which  has  produced  the  Celto-Bretonic  rogan  and  the  German  brechen. 
The  whistling  of  the  wind  has  by  imitation  given  rise  to  the  sound  of  s.  The  Persian 
sarse,  to  slide,  was  applied  to  the  serpent,  owing  to  the  noise  it  produced,  gliding  on 
the  grass.  Without  multiplying  examples  one  can  say  with  good  reason  that 
onomatopoeia  contributed,  along  with  the  emotional  determinism,  to  the  formation 
of  the  first  articulate  sounds  which  came  to  designate  certain  objects  and  pheno- 
mena. These  sounds  symbolise  something  outside  of  ourselves  and  internal  con- 
ditions. Repeated  and  fixed  by  habit,  they  would  be  the  roots  of  the  Indo-European 
languages,  according  to  Max  Miiller,  or  even  the  roots  of  all  languages,  according  to 
the  recent  doctrine  maintained  in  Italy  by  Trombetta. 

The  language  of  prehistoric  man,  who  lived  and  struggled  against  the  treach- 
erous and  terrible  elements  of  nature  in  the  palaeolithic  epoch,  more  than  one 
hundred  and  fifty  thousand  years  ago,  was  very  probably  monosyllabic  and  in- 
definite. By  slow  degrees  it  came  to  acquire  a  more  definite  character  in  subsequent 
epochs,  and  progressed  by  gradually  assuming  phonetic-articulate  demonstrative 
forms  of  language. 

Max  Miiller  1  has  reduced  the  number  of  monosyllabic  words  with  differentiated 
meaning,  made  use  of  by  the  Indo-European  races  in  their  infancy,  to  121. 

In  any  case,  it  seems  safe  to  say  that  modern  languages  became  developed  from 
roots  by  a  process  of  ramification,  contemporaneously  with  the  development  of 
human  thought  and  actions.  The  syllable  ma  or  am  must  have  been  one  of  the 
first.  It  is  found  in  many  primitive  tongues.  In  some  ma  signified  water,  whence 
perhaps  the  word  mare.  In  other  cases  it  gave  rise  to  many  similar  words  all 
signifying  "  hand  "  ;  thus  the  Italian  "  mano  "  and  the  words  "  mara,"  "  marra," 
"  murra,"  "  malla,"  "  mulla,"  of  the  Australian  tongues. 

In  others  again  it  gave  rise  to  the  words  "  mitir,"  "  mater,"  "  madre,"  "  mutter," 
"  mother,"  all  of  which  mean  mother. 

The  ramification  is  demonstrated  by  the  majority  of  the  roots  of  the  Indo- 
European  languages.  Thus  from  the  root  fac  have  come  the  branches  facio,  factio, 
facultas. 

It  is  held  that  thoughts  became  expressed  by  these  men  not  merely  by  gestures 
but  also  by  monosyllables  with  different  inflexions  to  express  different  things. 
Later,  the  monosyllables  became  associated  or  combined  with  one  another  to 
express  other  things,  and  so  by  agglutination  other  languages  came  to  be  derived 
from  these.  Contractions  of  these  additions  gave  rise  to  tongues  with  inflexions, 
which  belong  to  the  more  advanced  races.  Even  to-day  one  can  detect,  in  the 
tongues  of  savage  and  semi-savage  peoples,  the  various  phases  of  development  of 


1  Max  Miiller.     The  Monist.     1891. 


INTELLIGENCE  AND  LANGUAGE  229 

of  communication  between  animals  (song,  calls)  ;  it  is  understood  by  other 
members  of  the  same  species  and  is  capable  of  reproducing  identical  emotions 
in  them. 

All  auditory  images  which  are  not  words  (sounds,  musical  tones,  etc.) 
are  more  emotional  than  cognitive.  To  become  cognitive  it  is  necessary 
that  they  be  associated  with  a  sensory  image  of  the  concrete  object  to  which 

the  more  advanced  languages.  Those  races  whose  cerebral  development  has 
suffered  arrest  from  one  cause  or  another  have  idioms  which  present  the  characters 
of  a  primitive  language.  The  clicking,  and  sometimes  crackling,  sounds  of  the 
Hottentots  and  Bushmen  are  a  living  demonstration  of  what  the  language  of  the 
first  human  beings  may  have  been. 

The  development  of  intellect  and  language  has  taken  an  extraordinarily  long 
time  in  the  lower  races.  One  has  only  to  remember  that  many  tongues  and 
dialects  are  of  comparatively  recent  origin.  The  Cuschitic  tongues  and  the  Berber 
dialects  are  devoid  of  literature,  and  do  not  yet  possess  any  true  writing.  The 
uneducated  peasants  of  Lithuania,  until  a  few  years  ago,  spoke  a  language  which 
approximated  to  Sanscrit.  The  oldest  documents  of  Lithuania  do  not  go  any 
further  back  than  the  sixteenth  century.  Tongues  that  owe  their  origin  to  agglu- 
tination are  to  be  found  in  the  inferior  races  of  America,  Africa,  Oceania,  and  Asia 
(Mongolians  and  Uralo-Altatians).  Groups  of  Copts  and  Berberians  have  tongues 
that  are  intermediate  between  the  agglutinative  and  inflexive ;  these  have  all  been 
arrested. 

The  new  words  which  are  formed  with  suffixes  and  affixes,  to  keep  pace  with  the 
growth  of  science  and  industry  and  our  capital  of  ideas,  demonstrate  the  indefinite 
continuation  of  arborisation  in  every  branch  of  the  evolved  tongues.  Take,  e.g., 
the  root  spac  and  its  Greek  derivative  "  scopos."  One  need  only  mention  a  few 
words  formed  in  recent  times  in  consequence  of  the  advance  of  science — e.g.  micro- 
scope, spectroscope,  telescope.  The  whole  series  would  indeed  be  a  long  one. 
There  is  no  doubt  that  the  tongues  of  civilised  people  have  been  enriched  by  new 
words  with  a  truly  marvellous  rapidity. 

According  to  a  calculation  of  Max  Miiller  the  cuniform  inscriptions  of  Persia 
contain  scarcely  379  words.  The  hieroglyphics  of  the  doctors  of  ancient  Egypt 
amount  to  not  more  than  658  words.  The  Old  Testament  is  written  with  5642 
words  and  the  plays  of  Shakespeare  with  no  less  than  15,000.  The  English 
language  which,  in  the  earlier  editions  of  Webster's  and  Robertson's  dictionary, 
amounted  in  all  to  43,566  words,  has  increased  to  250,000.* 

This  development  of  language  is  almost  parallel  with  that  of  the  senses  and 
intellect.  It  is  very  probable,  as  Geiger  asserted,  that  in  the  period  of  formation  of 
the  Aryan  tongues  only  one  colour  was  known,  the  blue  of  the  sky  not  being  dis- 
tinguished from  the  green  of  the  meadows,  the  grey  of  the  earth  from  the  deep 
yellow  of  the  rocks  and  the  golden  dawn  from  the  red  twilight.  It  is  said  that  the 
presence  of  an  intelligent  human  being  on  the  face  of  the  earth  dates  back  about 
200,000  years.  The  finding  of  identical  utensils  in  the  districts  of  the  Seine,  the 
Thames,  in  South  Africa,  in  the  Indies,  in  Spain,  leads  us  to  believe  that  human 
beings  in  the  palaeolithic  or  pre-palaeolithic  epochs  already  inhabited  different  parts 
of  the  earth.  Then  men  must  have  attained  a  remarkable  cerebral  development  in 
the  mesolithic  period  which  commenced  eighty  thousand  years  ago.  Perception  of 
colours  was  slow  and  gradual.  Besides  their  imperfection  in  design  and  the  irre- 
gularity of  their  lines,  the  paintings  of  savages  show  no  blending  of  colours. 
Savages  do  not  perceive  the  shades  (nuances)  and  sesthetic  intonations  dependent 


1  Max  Miiller.     The  /Science  of  Language.     2nd  edit. ;  and  Lemons  sur  la  science 
du  langage. 


230  THE  MECHANISM  OF  THE  BRAIN 

each  refers.  The  song  of  the  nightingale  or  the  sound  of  the  violin  is  cognitive 
only  when  we  have  the  visual  or  symbolic  image  of  the  nightingale  or  the 
visual  and  tactile  image  of  the  violin. 

Whilst  the  visual  and,  to  some  extent,  also  the  tactile  zone  furnish  us 
with  the  immense  objective  material  of  nature,  to  be  translated  into  language, 
the  auditory  zone  provides  us  with  emotional  material,  with  which  nature 

on  these.  The  author  has  seen  Ethiopian  paintings  of  the  Madonna  in  which  the 
abrupt  change  from  blue  to  yellow  and  from  green  to  red  was  very  noticeable. 
Painting,  introduced  perhaps  by  Cleofante  Corintio,  was  monochromatic.  It 
became  transformed  into  the  polychromatic,  with  fundamental  colours,  in  the 
Etruscan  ceramics  and  in  the  paintings  of  the  Pompeian  period.  Even  the  pre- 
Raphaelite  school  shows  a  relative  poverty  of  tints.  Perceptive  insufficiency  with 
regard  to  colours  characterises  the  works  of  art  of  certain  painters  ;  and  Daltonism, 
now  quite  common,  reveals  the  late  evolution  of  the  sense  of  colours,  even  in  some 
individuals  of  more  advanced  races. 

Very  much  the  same  thing  may  be  said  with  regard  to  hearing  and  music.  The 
human  voice,  produced  by  the  most  perfect  musical  instrument,  expresses  in  the 
articulate  word  the  language  of  thought,  and  in  song  that  of  the  emotions.  Music 
and  speech  have  sprung  from  one  and  the  same  stem — the  modulation  of  the  human 
voice.  Rhythm,  as  it  is  in  nature,  contributes  to  the  passional  tone.  The  Adagio, 
Andante,  Allegro,  Presto,  and  the  inflexions,  depending  as  they  do  upon  infinite 
variations  of  movements  of  the  vocal  cords,  reflect  in  song  all  the  human  emotions 
— love,  hatred,  tenderness,  contempt,  jealousy,  joy,  anguish,  disdain — in  short,  the 
whole  gamut  of  pleasure  and  of  pain,  the  two  fundamental  sentiments. 

The  songs  that  accompanied  the  dances  of  our  ancient  forefathers  were  mono- 
tonous, and  had  a  good  deal  of  the  recitative  about  them.  Even  in  our  own  day 
the  songs  of  savages  are  impressed  on  monotonous  motifs  in  which  rhythm  is  the 
prevailing  feature,  accompanied  by  exaggerated  gesticulation,  leaping  and  shout- 
ing. Mythological  and  heroic  legends  were  expressed  in  rhythmic  language  full  of 
metaphor,  prone  to  awaken  intense  passional  states,  and  were  sung.  The  harp, 
the  lyre  and  the  flute  of  the  Egyptians,  the  lyre  of  David  which  exercised  such  an 
influence  over  his  people,  the  numerous  choruses  of  Euripides  which  provoked 
veritable  accessions  of  ecstasy  in  women,  and  the  musical  triumphs  of  Nero,  were 
very  far  removed  from  the  complex  harmonies -and  the  infinite  inflexions  of  modern 
music,  which  reaches  a  marvellous  sentimental  height.  One  can  notice  to-day  a 
tendency  of  modern  music  to  free  itself  from  the  human  passional  element  in  order 
to  acquire  an  independent  dominion,  a  new  creation  of  the  human  spirit — a  sort  of 
musical  restheticism.  Similar  arguments  are  applicable  to  smell  and  taste. 

Everything  points  to  a  slow  evolution  of  the  intellect  and  of  language.  It  is 
reasonable  to  suppose  that  many  roots  were  the  same  in  all  parts  of  the  world 
where  human  beings  were  to  be  found,  because  the  structural  conditions  that  gave 
rise  to  the  first  monosyllabic  sounds  were  identical.  There  is  no  doubt  that  variety 
in  external  nature  did  not  fail  to  exercise  a  great  influence  both  on  the  development 
of  the  brain  and  on  onomatopoeia,  but  it  is  equally  certain  that  the  blowing  of  the 
wind,  the  crashing  of  lightning,  the  murmur  of  running  water,  were  the  same  every- 
where. The  analogies  and  the  differences  found  by  glottologists  can  be  explained 
along  these  lines. 

The  law  that  ontogenesis  (development  of  the  individual)  is  a  recapitulation  of 
phylogenesis  (development  of  the  species)  is  confirmed  by  the  evolution  of  language 
in  the  infant,  for  there  we  have  a  synthetic  presentation  of  starting  points  that  are 
common  to  all  human  languages.  Briefty,  the  first  linguistic  manifestations  of 
the  infant  are  the  sounds  a  and  e ;  in  the  adult  a  is  expressive  of  pleasure,  and  of 
suffering.  The  senso-muscular  mechanics  of  a  are  more  simple  than  those  of  e,  but 


INTELLIGENCE  AND  LANGUAGE  231 

plagues  or  soothes  our  senses,  and  with  linguistic  material  which  has  gone  on 
accumulating  through  a  long  process  of  evolution,  facilitating  the  rapid  and 
marvellous  development  of  thought. 

The  content  of  language  emanates  from  the  field  of  the  concrete  images 
on  the  one  hand  (sensory  zones)  and  from  that  of  the  abstractions,  syntheses 
and  logic  on  the  other.  The  development  of  a  train  of  thoughts,  in  logical 

neither  sound  has  any  ideative  content  in  the  case  of  the  infant ;  the  consciousness 
is  just  beginning  to  dawn.  Later  on,  the  first  labial  sounds  appear  on  the  scene, 
m  and  p,  in  combination  with  vowels,  forming  syllables  which  have  no  other  signifi- 
cance than  that  of  a  reflex  motor  impulse  and  imitative  activity  as  exhibited  in  the 
infant,  which  commences  to  find  pleasure  in  a  certain  acoustic  effect.  Subsequently 
the  infant  pronounces  the  sounds  ma,  am,  nl,  ml,  ach  and  6.  Before  the  end  of  the 
first  year  it  recognises  objects  and  some  persons.  There  is  a  commencing  distinction 
of  the  ego  from  the  external  world.  The  infant  shows  a  distinct  tendency  to  pro- 
nounce words,  but  the  psycho-motor  apparatus  has  not  yet  attained  such  develop- 
ment as  will  permit  pronunciation  of  bisyllabic,  trisyllabic  or  still  more  complicated 
words,  and  it  therefore  simplifies  them.  Thus,  it  does  not  say  "  mama  "  from  the 
beginning,  but  simply  "  ma-a-a,"  the  second  syllable  being  vowelled.  It  has  always 
seemed  to  the  author  that  one  might  perceive  in  this  sound,  which  is  amongst  the 
first  utterances  of  our  infants,  the  root  ma  of  man's  infancy,  from  which  thousands 
of  words  have  been  developed. 

Features  that  are  constant  in  the  development  of  the  language  of  the  infant  are 
syllabic  shortening  and  vocalisation  of  words.  Mothers,  who  (like  Paola  Lom- 
broso),  observe  carefully  and  fondly  the  mental  development  of  their  children  are 
well  aware  that  the  first  words  are  monosyllables  and  that  bisyllables  come  after 
these.  The  infant  says  "  kolat  "  instead  of  "  chocolate  "  (Taine)  or  says  "  amama  " 
instead  of  "  grandmama."  It  is  not  too  much  to  suggest  that  one  may  detect,  in 
this  phase  of  language  in  the  infant,  some  of  the  characters  that  belonged  to  the 
initial  periods  of  languages  that  are  now  highly  advanced,  and  are  to  be  found  even 
to-day  in  the  present  grade  of  development  of  language  amongst  some  Hottentots 
and  certain  Australian  tribes.  In  these  tongues  or  dialects  there  is  a  prevalence  of 
monosyllabic  words  and  cries. 

Even  in  Europe  there  may  be  found,  here  and  there,  small  groups  of  men  and 
women  who  have  remained  in  a  poor  and  primitive  condition,  incapable  of  pro- 
nouncing well  words  of  four  syllables.  The  infant,  again,  changes  vowels  and  con- 
sonants, and  even  substitutes  syllables,  and  in  this  fashion  presents  a  miniature 
view  of  the  long  course  that  has  been  followed  in  the  period  of  formation  of  modern 
languages. 

The  vowel  sounds  are  not  decisive  but  at  most  intermediate — io,  au,  ae,  iau,  ou. 
The  consonants  are  often  changed,  instead  of  "  cream  "  the  infant  says  "  team." 
This  may  also  serve  to  explain  why  the  same  roots  may  have  acquired  different 
sounds  in  passing  through  the  dialects  or  primitive  tongues  of  different  peoples. 
It  may  also  serve  to  explain  how  it  came  to  be  that  the  Sanscrit  "  spac  "  became 
"  seep  "  in  Greek.  The  evolutionary  process  is  the  same  in  the  development  of  the 
language  of  humanity  and  in  that  of  the  infancy  of  modern  man. 

Another  argument  in  favour  of  speech  having  had  its  first  beginnings  in  vowels 
and  then  in  monosyllables  is  to  be  drawn  from  pathology.  We  meet  with  human 
beings  whose  brains  have  not  reached  the  grade  of  development  that  is  common  to 
other  contemporary  men  of  the  same  race,  but  have  been  arrested  at  one  of  the 
lower  levels.  The  general  law  is  that  degeneration  retraces  in  a  retrograde  direction 
the  various  phases  that  have  been  passed  through  in  the  course  of  evolution.  Thus 
it  happens  that  we  may  detect,  in  the  psycho-anthropological  degradation  of 
modern  man,  the  various  phases  of  development  belonging  to  evolved  tongues. 


232  THE  MECHANISM  OF  THE  BRAIN 

order,  is  possible  only  by  means  of  language.  Language  also  translates 
emotions  and  sentiments,  movements,  conduct,  and  all  states  of  consciousness 
into  symbols.  Despite  opinions  to  the  contrary,  there  is  good  reason  to 
believe  that  language  normally  summarises  intelligence,  and  that  there 
exists  an  anatomical  intellectual  field  distinct  from  the  field  of  speech  con- 
sidered as  such.  Speech  may  be  disturbed  not  only  as  the  result  of  injury 

Many  of  these  patients  can  be  arranged  in  series.  Some  show  only  a  great 
poverty  in  their  vocabulary,  but  are  able  to  pronounce  all  words  well,  even  although 
they  do  not  understand  their  meaning.  Others  are  incapable  of  pronouncing  words 
of  complicated  construction.  They  can  utter  not  more  than  three  syllables  with 
some  syllabic  shortening,  or  some  syllabic  sounds  are  uttered  as  vowels.  Others, 
again,  simplify  several  syllables,  making  them  a  vowel — e.g.  maoni  for  macaroni, 
dottoe  for  direttore.  Some  express  all  the  syllables  as  vowels  without  shortening  the 
word.  I  have  had  under  my  care  a  classical  micro-cephalic  whose  brain  weighed 
about  one  quarter  of  the  average  normal  brain  weight.  At  twenty-four  years  he 
could  make  use  of  only  two  syllables,  ma  and  pa,  and  of  some  animal  calls  by 
which  he  expressed  the  fundamental  emotional  states  of  pleasure  and  of  pain,  and 
some  few  desires. 

It  should  be  noted,  however,  that  in  some  modern  languages,  even  the  more 
evolved,  like  French  and  English,  one  notices  a  tendency  to  simplification  of  words 
and  to  syllabic  contraction  by  a  law  of  adaptation.  Thus  the  Latin  word  episcopus 
becomes  by  a  series  of  simplifications  eveque  in  French ;  conoscere  becomes  in 
English  "  know."  This  is  due  to  a  selective  capacity  and  a  tendency  to  spare 
energy,  and  has  nothing  in  common  with  the  abbreviation  of  words  that  is  met  with 
in  those  whose  nervous  organs  have  not  been  developed  to  the  extent  requisite  for 
the  co-ordination  of  the  movements  necessary  for  a  complete  and  precise  articulation 
of  the  phonetic  symbols  of  thoughts. 

In  some  diseases,  consisting  in  a  slow  and  progressive  degeneration  of  the  brain, 
one  can  trace  the  various  steps  in  the  involution  of  language,  from  mere  verbal  im- 
poverishment to  vowelisation  and  monosyllabism.  The  story  of  writing  offers  us 
truly  interesting  proofs  regarding  the  question  of  the  genesis  of  language.  Man 
has  been  brought  by  his  structure  to  reproduce  his  images,  emotions  and  thoughts 
in  a  sensible  form,  no  matter  whether  these  have  been  got  from  the  eternal  and  varied 
language  of  nature  or  whether  he  has  formed  them  in  his  own  mental  world.  If  he 
imitates  forms  and  figures,  he  initiates  art ;  he  carves  out  the  lion-hunt  on  the 
Mycenaean  dagger,  and  rises  to  perfection  in  Phidias  ;  and  when  his  imagination 
reaches  the  highest  point  of  genius,  he  produces  marvellous  paintings  such  as  those 
of  the  vault  of  the  Sistine  Chapel  where,  one  might  say,  reality  "  e  rifatta  si  come 
pianta  novella.'1''  If  he  translates  his  thought  into  graphic  symbols,  he  creates  writing  ; 
but  this  was  preceded  by  other  symbols — the  mnemonic  signs  and  the  symbolic 
objects. 

Symbolic  objects  are  still  in  use  amongst  the  Malays  of  Sumatra,  and  consist  of 
packets  containing  pieces  of  salt  or  powder  or  smoking  herbs  which  respectively 
signify  love,  hatred  and  jealousy.  The  message  serves  to  express  one  of  these 
sentiments.  A  system  of  mnemonic  tokens  had  reached  a  high  grade  of  perfection 
among  the  Wampums  of  the  Redskins.  They  include  a  kind  of  beaded  rosary 
made  with  shells  of  different  colours,  or  embroideries  on  ribbons  which  serve  also  as 
belts,  or  message  sticks,  very  common  amongst  the  Malays,  the  Niam-Niam  and 
other  peoples.  Incisions  on  trees  or  pieces  of  wood  represent  the  first  step  towards 
writing,  properly  so  called.  In  the  sepulchral  grottoes  of  the  quaternal  period  at 
Aurignac  (Dordogne)  tablets  have  been  found  bearing  symbolic  signs  like  those 
actually  prevalent  amongst  the  Eskimos,  the  Yakuts,  the  Macousis  of  Guiana,  the 
negroes  of  the  West  Coast  of  Africa.  Knotted  cords  are  in  use  amongst  the 


INTELLIGENCE  AND  LANGUAGE  233 

to  the  organs  immediately  concerned  in  speech-mechanism  but  also  when 
the  mechanisms  that  are  formative  of  the  mental  content  are  injured  (concrete 
images  and  abstract  ideas) ,  and  in  addition  when  there  is  interruption  of  the 
paths  which  connect  the  various  fields  of  images  and  notions  and  render 
possible  the  logical  process. 

It  is  true  that,  in  diagrams,  we  are  compelled  to  represent  the  intellectual 

Ostiakis,  the  Angolian  Negroes,  the  Malgasci.  The  ancient  Peruvians  used  to  express 
happenings  and  ideas  with  the  aid  of  knots  differently  made  and  variously  disposed. 
To  each  knot  on  the  cord  there  was  attached  a  thin  cord,  and  each  thin  cord  had  a 
different  colour,  all  having  several  knots  diversely  arranged.  The  knots,  the  colours 
and  the  thin  cords  had  a  meaning,  symbolic  of  thoughts  and  sentiments. 

Afterwards  came  writing  in  the  form  of  designs  expressing  a  certain  number  of 
ideas,  such  as  is  found  amongst  the  bushmen  and  the  Australians,  the  so-called 
pictography. 

From  pictography  was  derived  figurative  writing  in  the  form  of  the  hieroglyphics 
of  the  Egyptians,  Mexicans  and  other  peoples.  Hieroglyphics  are  designs  of  objects 
the  first  syllable  of  which  forms  a  part  of  the  word  it  is  desired  to  express.  These 
figures  had  thus  a  phonetic  value,  and  one  can  follow  the  transformation  of  the 
Egyptian  hieroglyphics  and  the  cuniform  writing  of  the  ancient  Assyrians.  The 
first  syllabic  writing  appears  to  have  been  made  by  the  inhabitants  of  the  island  of 
Crete,  this  evidently  being  more  ancient  than  that  of  the  Phoenicians  which  was 
derived  directly  from  pictography. 

With  the  appearance  of  writing  we  get  a  sign  of  distinction  between  barbarism 
and  civilisation.  When  writing  assumed  a  definite  character  and  came  to  fix  con- 
ventional and  indelible  signs  of  thought  and  action,  the  rate  of  human  progress 
accelerated  enormously,  because  writing  transmitted  to  successive  generations  the 
thought,  sentiments  and  knowledge  of  the  generations  that  went  before. 

In  retracing  the  story  of  human  evolution,  one  of  the  things  that  strikes  us  most 
is  the  constantly  increasing  tendency  to  substitute  movements  of  spoken  and 
written  speech  for  the  coarser  and  grosser  movements  by  means  of  which  primitive 
men  reacted  upon  the  external  world  and  exchanged  with  one  another  their 
thoughts  and  emotions.  In  proportion  as  the  capital  of  cognitions  increases  and 
sentiments  are  renewed,  we  get  a  preponderance  of  the  movements  concerned  in 
spoken  and  written  speech.  Writing  affords  a  means  whereby  the  consciousness  of 
young  generations  absorbs  much  more  quickly,  and  becomes  integrated  with,  the 
thought  and  work  of  those  that  preceded  them.  By  means  of  writing  man 
communicates  with  all  his  fellow-beings  scattered  throughout  the  world. 

The  old  mechanism  and  simple  methods  of  our  predecessors  would  be  insufficient 
for  the  needs  of  to-day.  Modern  man  is  not  an  isolated  and  independent  unit  but 
forms  a  part  of  the  whole,  to  the  life  of  which  he  gives  his  contribution,  and  from 
which  he  draws  the  elements  of  his  existence.  Every  intellect,  as  it  assumes  its 
own  character  and  form,  detaches  itself  from  the  Milky  Way  of  humanity,  which  is 
always  in  process  of  formation,  and  goes  to  form  part  of  a  planetary  system,  the 
laws  of  attraction  and  repulsion  of  which  he  must  necessarily  obey. 

To-day  the  solitary  man  is  either  a  primitive  or  a  sick  man.  One  can  only  look 
upon  him  as  a  discordant  note,  a  hindrance  to  the  evolution  of  the  race. 

Writing  and,  through  it,  the  press  form  the  great  arterial  system  in  which 
circulates  the  animating  current  of  human  solidarity.  The  old  individualism  is 
ridding  itself  of  the  old  futilities  and  is  rising  to  the  dawn  of  a  new  era  in  which  new 
sympathies,  embracing  extraneous  as  well  as  personal  interests,  are  being  kindled 
in  every  conscience. 

It  is  needless  to  discuss  whether  the  first  journal  was  that  which  appeared  in 
Venice  in  1536,  according  to  Voltaire,  or  in  1760  ;  the  difference,  with  respect  to  the 


234  THE  MECHANISM  OF  THE  BRAIN 

field  as  a  circumscribed  area,  but  it  should  be  remembered  that  it  really 
embraces  all  the  sensory  as  well  as  the  frontal  cortex. 

Intellectual  complexes  and  empirical  images  are  bound  up  with  words. 
The  words  "pen/'  "inkstand/'  correspond  each  to  its  respective  empirical 
image  in  the  visual  zone ;  the  words  "  puff,"  "  creak/'  "  whistle,"  to  their 
predominant  sensory  content  in  the  auditory  centre ;  the  words  "  rough," 
"  smooth/'  "  hectogram,"  clothe  corresponding  images  formed  by  the  tactile 
and  muscular  centres.  The  words  "school,"  "war,"  "humanity,"  have 
their  conceptual  content  in  that  part  of  the  brain  which  synthetises  the  large 
number  of  concrete  images,  emotions  and  experiences  that  go  to  constitute 
the  corresponding  conceptions.  The  suppression  of  any  one  of  the  sources 
of  images  produces  a  mnemonic  disturbance  of  speech  and,  if  the  image  which 
has  disappeared  is  not  substituted  by  another  connected  with  the  same  word, 
the  word  cannot  be  recalled. 

Substitution  is  quite  common.  If,  in  the  night-time,  we  hear  the  tolling 
of  a  bell,  the  word  "  bell  "  comes  up  before  us,  brought  to  consciousness  by 
the  auditory  percept.  The  same  word  comes  to  our  lips  during  the  day  when, 
passing  near  a  belfry,  our  eyes  light  upon  the  bell ;  one  of  these  images  alone 
is  sufficient  to  recall  the  auditory  or  kinsesthetic  image  of  the  word  "  bell." 

The  image  of  the  word  "  rose  "  is  awakened  when  we  smell  or  touch  a  rose 

time  employed  by  human  evolution,  is  a  negligible  quantity.  It  is  certain  that  a 
journal  was  published  in  Antwerp  in  1665  and  in  Germany  in  1616.  The  Weekly 
News  from  Italy,  Germany,  etc.  first  saw  the  light  in  1622,  and  the  first  French 
journal  appeared  in  1631.  When  we  reflect  that  the  number  of  letters  posted 
throughout  the  world  in  1888  was  1,700,000,000,  and  that  to-day  this  figure  has  been 
multiplied  more  thn  fivefold,  when  we  know  that  800,000  tons  of  letters  and  news- 
papers were  posted  in  Europe  alone  in  1883  and  that  after  twenty  years  even  this 
was  more  than  doubled,  we  cannot  help  wondering  what  life  will  be  like  to-morrow, 
as  regards  human  thought  and  sentiment,  human  labour  and  production. 

Whilst  primitive  man  had  to  conserve  and  defend  his  body  only,  modern  man 
has  to  develop,  conserve  and  defend  a  whole  moral  world  of  inestimable  value. 

Reflex  movements  have  become  greatly  complicated  and  transformed  into  the 
very  delicate  mechanisms  of  articulate  speech  and  writing  which,  though  still 
movements,  lead  the  community  to  action  that  is  always  more  complex  and  more 
multiform. 

The  spoken  or  written  word  synthetises  and  condenses  the  great  potency  of 
modern  man.  It  possesses  all  the  arms  that  are  requisite  for  conquest  and 
dominion  ;  it  is  grief  or  joy,  if  it  wounds  or  caresses  ;  it  is  love,  if  it  translates  into 
articulate  sounds  the  sympathy  of  two  beings  ;  it  is  suggestion,  if  it  transmits 
thoughts,  sentiments  or  actions  to  others  ;  it  exalts  and  humiliates,  wounds  and 
kills.  It  is  music  and  song  in  the  harmony  and  rhythm  of  the  voice ;  it  represents 
darkness  and  splendour,  peace,  tempest  and  hurricane  ;  it  penetrates  nature  and 
lays  bare  all  its  beauties,  the  sublimely  awful  and  the  terribly  threatening.  It  is 
painting  or  sculpture  when  it  presents  to  us  the  forms  and  colours  of  objective 
realities  or  of  the  products  of  phantasy  in  the  infinite  varieties  in  which  genius 
conceives  them;  it  is  science  if  it  translates  the  language  of  nature  and  its  forces  ; 
it  is  consciousness  when  it  communicates  to  us  the  notions  and  emotions  of  our 
fellow-beings  ;  it  is  the  synthesis  of  the  universe,  in  so  far  as  the  latter  is  perceived 
and  spiritualised  in  the  busy  workshop  of  the  brain,  which  perennially  reproduces 
the  world  in  the  form  of  thought  and  speech. 


INTELLIGENCE  AND  LANGUAGE  235 

in  the  dark,  or  when  we  see  it  from  a  distance.  Cases  occur  in  which  an 
extensive  cerebral  lesion  destroys  one  or  even  two  areas  of  images  that  refer 
to  the  same  object,  and  yet  the  word  persists.  One  single  area  may  thus 
suffice  to  reawaken  the  word,  especially  in  the  developmental  period,  if  the 
remaining  healthy  part  of  the  brain  attains  a  great  compensatory  develop- 
ment. Thus  is  explained  the  intelligence  of  some  blind  people,  based  as  it  is 
on  tactile  and  muscular  memory,  as  exemplified  in  the  well-known  cases  of 
Laura  Bridgmann  and  Helen  Keller.* 

In  such  cases  the  cortical  centres  of  the  injured  sensory  organs  have 
already  assumed  relations  with  other  cortical  fields,  so  that  the  construction 
of  mental  products  by  means  of  the  associative  paths  is  more  easy  than  it 
would  otherwise  have  been. 

Great  elaboration  and  fusion  of  the  various  percepts  depends  not  only 
on  irradiation  from  one  centre  of  perception  to  all  the  other  sensory  centres 
but  also  on  convergence  of  the  products  of  the  various  perceptive  centres 
upon  one  common  area,  that  of  language  and  of  the  frontal  lobes. 

Most  authorities  who  follow  Broadbent  and  speak  of  an  intellectual  centre 
distinct  from  the  area  of  language  (Kussmaul,  Charcot,  Bernard,  Ballet, 
Lichteim  and  several  others)  speak  entirely  from  an  abstract  point  of  view, 
and  the  diagrams  they  have  drawn  are  pure  abstractions  unaccompanied  by 
adequate  psycho -anatomical  explanation. 

The  localising  doctrine  that  those  authorities  put  forward  does  not  find 
favour  with  many  other  neurologists  who  speak  with  no  less  authority. 
Bastian,  e.g. ,  declared  that  he  was  unable  to  find  from  the  clinical  data  any 
clear  evidence  proving  the  existence  of  a  defect  of  speech  which  could  be 
explained  by  supposing  the  existence  of  a  lesion  in  the  centre  for  the  concepts 
or  in  the  course  of  its  afferent  or  efferent  fibres.1 

The  existence  of  areas  for  images  of  objects  distinct  from  those  for  images 
of  speech  is  proved  by  the  fact  that  the  word-image  is  quite  distinct  from 
the  image  of  the  object  itself,  to  which  it  refers.  It  often  happens  that 
we  see  an  object  or  evoke  its  image  without  being  able  to  name  it,  and, 

*  The  case  of  Helen  Keller  (Giulio  Ferreri.  Lo  sviluppo  della  intelligenza  nella 
privazione  simultanea  delVudito  e  della  vista.  International  Congress  of  Psychol- 
ogy 1905),  shows  that  the  intellect  can  only  be  developed  by  means  of  the  senses ; 
that  when  some  senses  are  suppressed  their  functions  may  be  compensated  by 
increased  activity  of  other  senses.  What  is  of  more  importance,  however,  is  the  fact 
that  Helen  Keller  became  blind  and  deaf,  and  therefore  also  mute,  at  the  age  of 
nineteen  months — i.e.  at  a  time  when  the  sensory  centres  of  hearing  and  of  sight 
had  already  attained  a  certain  degree  of  development,  when  they  had  organised 
and  stored  a  capital,  small  though  it  was,  of  auditory  and  visual  images  of  things 
and  of  words,  sufficient  to  furnish  an  important  starting  point  for  the  recognition  of 
the  external  world  by  means  of  other  senses  and  subsequent  mental  constructions. 
I  have  often  noticed  that,  in  the  case  of  the  blind,  the  mind  develops  more  readily 
in  those  who  become  blind  some  years  after  birth — i.e.  after  the  cortical  fields  have 
attained  a  certain  development  and  have  actually  exercised  their  functions. 

1  Bastian.     Aphasia  and  other  Speech  Defects.     London,  1898. 


236  THE  MECHANISM  OF  THE  BRAIN 

similarly,  we  often  remember  the  name  of  an  object  whose  image  we  cannot 
recall. 

Clinical  observations  prove  that,  in  the  case  of  certain  lesions,  the  faculty 
of  recognising  common  objects  by  means  of  sight,  touch  or  hearing  may  be 
preserved  although  the  name  cannot  be  recalled.  All  this  goes  to  show 
clearly  that  the  two  images  are  distinct,  and  furnished  by  two  different 
anatomical  fields,  associated  with  one  another.  Further,  the  story  of  the 
development  of  thought  and  of  speech  provides  additional  proofs  of  the 
soundness  of  this  view.  The  infant  has  already  acquired  a  significant  capital 
of  images  of  persons  and  of  objects  before  verbal  images  of  these  are  formed. 
Animals,  too,  which  do  not  speak,  recognise  a  number  of  things  and  persons. 

In  this  regard,  the  abstract  concepts  present  a  much  more  difficult  problem. 
These  cannot  be  recalled  except  by  means  of  the  sensible  forms  of  the  respec- 
tive words  with  which  they  are  indissolubly  bound  up.  There  is  no  doubt 
that  we  are  able  to  produce  the  image  of  a  man  without  need  of  the  word 
"  man,"  but  we  cannot  in  any  way  represent  to  ourselves  the  concept  of 
humanity  without  the  word  "humanity."  No  doubt  we  can  figure  to 
ourselves  humanity  by  dividing  the  abstract  concept  into  concrete  and 
separate  images  of  different  men  and  different  human  attributes  of  which 
it  is  made  up,  but  here  we  no  longer  have  an  abstract  conception.  The 
coalescence  of  the  word  with  the  abstract  concept  and  the  impossibility  of 
separating  these  do  not  warrant  us  in  denying  that  each  is  formed  in  a  different 
area.  From  another  source  we  can  draw  good  reasons  for  considering  these 
two  factors  as  separate,  both  in  mechanism  and  in  site.  An  imbecile,  e.g., 
can  learn  to  pronounce  the  word  "  humanity  "  without  having  any  conception 
of  "  humanity,"  just  as  the  infant  calls  everyone  he  sees  "  Dada  "  because  he 
does  not  yet  possess  the  abstract  concept  of  "  father,"  and  does  not  perceive 
the  difference  between  other  men  and  his  father,  even  though  the  latter 
caresses  him  much  more.  If,  then,  the  word  can  be  learned  and  pronounced, 
completely  void  of  any  conceptual  content,  both  by  infants  and  by  imbeciles, 
and  if  it  is  true  that  even  dements,  when  their  intelligence  is  resolved  into 
its  elements,  may  pronounce  many  words  that  have  no  longer  any  meaning 
to  them  and  are  quite  void  of  conceptual  content,  the  concepts  having  been 
lost  in  the  wreckage  of  mind,  one  must  conclude  that  the  words  which  clothe 
the  concepts  have  a  distinct  seat  of  formation  and  that  the  concepts  may 
disappear  and  the  words  remain.  The  abstract  conception  is  the  product 
of  fusion  of  the  concrete  images  into  which  it  may  be  decomposed,  if  we  seek 
to  analyse  it — images  which  all  vibrate  together  on  the  threshold  of  con- 
sciousness and  in  the  anatomical  field  of  the  word  which  symbolises  all  of 
them.  If,  however,  the  word  disappears,  owing  to  a  lesion  of  the  area  in  which 
verbal  images  are  formed  and  conserved,  the  concept  can  no  longer  be  repro- 
duced. At  most,  it  may  remain  in  a  latent  state  because  all  the  material 
that  goes  to  form  it  remains  intact  and  capable  of  being  reproduced.  From 
all  we  have  said  on  this  subject  it  is  clear  that  all  the  sensory  areas  of 
the  cerebral  mantle,  besides  that  of  the  syntheses  and  of  logic,  with  which  we 
will  afterwards  deal,  must  be  regarded  as  intellectual  fields  of  language, 


INTELLIGENCE  AND  LANGUAGE  237 

inasmuch  as  they  furnish  concrete  images  of  concepts  which  constitute  the 
content  of  speech.  This  view  facilitates  our  comprehension  of  the  different 
varieties  of  amnesic  aphasia. 

The  auditory  and  visual  sensory  images  of  speech  are  found  to  be  com- 
posed of  a  series  of  sensory  components  which  by  their  combination  form 
at  the  outset  the  image  of  the  object,  and  subsequently  the  verbal  image. 
If  these  components  are  evanescent,  so  that  they  do  not  succeed  in  becoming 
combined  and  represented  by  virtue  of  their  own  inherent  power,  or  if  they 
lack  vividness,  as  some  psychologists  say,  the  image  of  the  word  will  not  be 
recalled.  The  concrete  image,  e.g.,  of  a  key  and  the  image  of  the  word 
"  key  "  are  made  up  of  a  series  of  sensory  components — the  form  of  the  key 
(visual  image),  the  weight  and  the  tactile  image  of  the  key,  and  then  the 
image  of  the  iron  of  which  the  key  is  made,  the  noise  of  the  key  (acoustic 
image),  when  a  door  is  locked,  as  when  Dante  makes  Count  Ugolino  say : 
"  Sentii  chiavar  Fuscio  di  sotto  a  Forrible  torre,"  the  thermic  sense  of  the  key 
when  taken  in  the  hand,  and  especially  the  muscular  sense  of  the  movements 
involved  in  the  action  of  turning  the  key  in  the  lock. 

If  these  images  are  evanescent  and  almost  beyond  our  grasp,  if  the 
nervous  waves  do  not  reach  their  destination  owing  to  defect  of  initial 
energy  and  necessary  intensity,  the  image  of  the  key  will  not  be  capable  of 
recall  or,  if  it  is  represented,  the  word  "  key  "  will  not  arrive  at  the  focal  point 
of  pronunciation.  One  can  here  invoke  the  physical  law  that  resistance  is 
in  inverse  ratio  to  the  excito-motor  force.  If,  in  these  cases,  the  memory- 
images  are  intensified  by  actual  stimuli  (as  when  we  put  the  key  into  the  hand 
of  the  amnesic  patient),  the  word  in  question  soon  becomes  recalled  and 
pronounced,  especially  if  the  amnesic  person  goes  through  the  action  of 
opening  a  door.  We  have  here  an  example  of  asthenic  amnesia. 

If  we  admit  the  existence  of  distinct  fields,  consisting  of  specialised 
elements,  where  images  of  objects  and  verbal  images  are  formed  and  registered 
(auditory,  visual  and  kinsesthetic  images),  we  must  agree  that  a  paretic 
condition,  not  to  speak  of  actual  destruction,  of  the  various  fields,  must 
consequently  bring  about  an  incapacity  to  reproduce  a  more  or  less  con- 
siderable number  of  the  respective  images.  It  is  in  this  way  we  get  various 
forms  of  amnesia  or  amnesic  aphasia. 

Sometimes  it  happens  that  individuals  who  formerly  were  ready  and 
felicitous  in  their  use  of  the  store  of  words  they  had  acquired  during  the 
period  of  education  arrive  at  a  time  in  life,  often  not  very  far  advanced, 
when  they  lose  that  faculty  that  made  them  ready,  subtle  speakers,  rich  in 
linguistic  resource,  able  to  adapt  to  each  thought  the  adequate  word  and 
give  to  each  object  the  proper  name. 

There  are  some  individuals  who  have  a  highly  educated  visual  centre  of 
speech,  as  the  result  of  extensive  reading  which  has  enabled  them  to  accumu- 
late a  rich  store  of  notions,  which  is  at  the  service  of  the  whole  intellectual 
and  linguistic  mechanism.  If,  however,  they  read  so  largely  that  they  come 
to  throw  an  excessive  strain  on  the  visual  centre,  they  begin  to  experience 


238  THE  MECHANISM  OF  THE  BRAIN 

difficulty  and  sometimes  an  incapacity  to  reproduce,  with  the  same  prompt- 
ness as  formerly,  the  images  which  render  their  language  truly  rich  and 
incisive. 

If  these  forms  of  verbal  amnesia  have  hitherto'  escaped  clinical  analysis 
they  are  nevertheless  of  great  value  in  helping  us  to  a  better  understanding 
of  the  functional  mechanism  of  the  brain.  Cerebral  fatigue  and  depressive 
states  of  mind  furnish  numerous  and  various  examples  of  the  dynamic 
(physical)  law  which  regulates  the  function  of  the  brain. 

The  intrinsic  constituent  elements  of  speech,  considered  per  se,  now 
deserve  some  attention. 

In  the  modern  man  who  can  read  and  write,  these  components  are  at 
least  three  in  number  :  (1)  the  auditory  image  and  (2)  the  visual  image  of 
speech,  these  being  impressive  components  ;  (3)  the  articulatory-kinsesthetic 
image  and,  according  to  many,  the  graphic-kinsesthetic  image  (expressive 
components).  Authorities  are  not  all  agreed  as  to  the  relative  importance 
to  be  attached  to  these  components.  While  Charcot  and  the  writer  have 
recognised  the  greatest  formative  and  regulative  power  of  speech  in  the 
acoustic  images,  Strieker,  Bastian  and  some  others  accord  the  highest 
importance  to  the  articulatory-kinsesthetic. 

Equal  importance  may  be  attached  to  both.  No  doubt  the  subjective 
method  renders  great  service  in  the  study  of  language,  but  its  value  should 
not  be  exaggerated. 

In  the  case  of  those  who  read  and  write  the  visual  verbal  image  comes 
into  play,  and  in  some  men  it  plays  a  preponderant  part. 

These  three  or  four  categories  of  images  have  their  cortical  fields  in  the 
evolutionary  zones  of  the  respective  fundamental  sensory  and  motor  areas, 
as  mentioned  in  Chapter  I. 

These  cortical  fields  are  linked  up  with  one  another  by  means  of  associa- 
tive fibres,  and  it  is  very  natural  that  interruption  of  these  paths,  by  breaking 
the  communication  between  two  or  more  groups  of  cortical  units,  should 
hinder  the  formation  of  the  complex  product  which,  as  a  matter  of  fact, 
results  from  the  combination  of  elementary  functional  products  of  many 
cell-groups.  A  considerable  amount  of  careful  analysis  has  served  to  make 
clear  the  great  importance  of  the  association-paths,  and  has  enabled  us  to 
distinguish  a  number  of  different  clinical  conditions  which  correspond  with 
lesions  in  the  various  paths.  These  are  the  subcortical  and  transcortical 
aphasic  disturbances. 

The  process  of  association  which  gives  rise  to  speech  considered  per  se — 
i.e.  independently  of  the  content  of  thought — is  governed  by  fundamental 
laws,  amongst  which  the  more  evident  are  (1)  the  hierarchic  preponderance 
of  one  over  the  other  components  of  language ;  (2)  the  law  of  individual 
variety.  It  is  a  probable  hypothesis  that  the  phonetic  or  acoustic  centre  of 
articulate  sounds  is  the  first  to  be  differentiated.  Even  in  the  infant  the 
first  articulate  sounds  are  only  fragments  of  the  words  heard.  It  is  common 
knowledge  that  only  at  a  much  later  period  is  the  infant  able  to  repeat  and 


INTELLIGENCE  AND  LANGUAGE  239 

articulate  a  word,  the  phonetic  image  of  which  has  already  been  registered 
for  some  considerable  time.  In  this  way  there  come  to  be  established  not 
only  relations  between  the  acoustic  centre  and  the  centre  of  articulation  of 
the  word,  wherever  that  be,  but  also  a  species  of  regulating  influence  exercised 
by  the  former  over  the  latter,  the  articulate  sound  manifesting  itself,  as  it 
were,  under  the  protection  of  the  acoustic  image  of  the  word_  Should  the 
acoustic  image  fail  to  be  represented,  or  should  there  be  interruption  of  the 
associative  paths,  so  that  the  acoustic  nerve- waves  fail  to  reach  the  cortical 
motor  groups,  the  word  will  be  entirely  lacking,  or  will  be  altered  in  form. 

The  acoustic  image  exercises,  in  addition,  a  regulative  influence  over  the 
visual  image  of  speech.  Under  present-day  scholastic  methods  the  infant 
does  not  learn  to  read  until  after  the  acoustic-motor  organ  is  functionally 
perfected.  Only  at  a  much  later  period  are  the  visual  images  of  letters, 
syllables  and  words  modelled  on  the  acoustic,  and  perhaps  also  on  the 
kinsesthetic,  images,  and  they  will  not  be  recalled  except  by  the  acoustic  or 
kinsesthetic  images,  or  both  together. 

This  law  has  an  important  bearing  upon  questions  concerning  aphasia, 
as  also  upon  questions  of  psychology.  It  serves  to  explain  individual 
variations.  It  is  a  fact  that  word-blindness  very  often  results  from  a  lesion 
of  the  auditory  area  of  speech,  even  when  the  visual  area  of  speech  has  been 
spared. 

The  mechanism  of  language,  as  already  mentioned,  is  much  more  simple 
in  illiterate  persons.  In  them,  only  the  acoustic  images  come  into  play. 
These  excite  the  motor  images,  which,  in  turn,  are  resolved  into  co-ordinate 
movements  of  the  apparatus  concerned  with  speech  articulation. 

In  educated  persons  the  mechanism  becomes  more  complex,  inasmuch 
as  other  factors,  varying  in  importance  and  value  in  different  cases,  become 
associated  with  the  two  just  mentioned. 

If  we  follow  the  different  stages  in  the  education  of  the  infant,  as  it  learns 
to  read  and  write,  we  can  readily  verify  the  fact  that  the  graphic  symbols 
(written  syllables  and  words)  have  their  correlatives  in  the  auditory  symbols 
with  which  the  child  is  already  acquainted.  A  relation  is  consequently 
established  between  the  acoustic  image  and  the  visual  image  of  the  word,  the 
former  preponderating  over  the  latter,  because  the  graphic  image  has  no 
significance  for  the  child,  apart  from  that  given  to  it  by  the  acoustic  or 
phonetic  image.  So  intimate  does  the  association  between  the  two  become 
that  it  is  difficult  for  the  visual  image  to  be  represented  alone,  without 
determining  the  pronunciation  of  the  respective  word. 

In  the  majority  of  those  who  are  more  or  less  practised  in  reading,  the 
sight  of  an  object  does  not  recall  the  graphic  symbol  unless  through  the 
acoustic  image,  the  paths  of  communication  of  the  latter  being  more  exercised 
and  more  pervious.  Heredity,  education,  occupation  and  practice,  besides 
other  contingencies  in  life,  may  nevertheless  reinforce  the  visual  word- 
images  to  such  an  extent  that  they  acquire  a  very  high  value  in  the  physio- 
anatomical  mechanism  of  speech. 

Once  the  system  is  constituted  and  dynamic  relations  established  between 


240  THE  MECHANISM  OF  THE  BRAIN 

the  various  fields,  it  is  clear  that  disappearance  of  one  of  these  will  induce 
a  disorder  in  the  function  of  all  the  others.  It  is  clear,  too,  that  this 
disturbance  will  be  more  pronounced  the  greater  the  regulative  influence 
exercised  by  one  over  the  others,  and  consequently  over  the  movement  of 
thought.  Suppression  of  the  acoustic  image  gives  rise  also,  in  the  majority 
of  men,  to  inhibition  of  reproduction  of  the  visual,  the  articulatory-kinaesthetic 
and  the  graphic-kinsesthetic  images. 

Disappearance  of  the  graphic-visual  image  leads  to  inhibition  of  the  graphic 
kinaestfretic  centre  of  speech.  Not  infrequently  it  gives  rise  at  the  same 
time  to  disorder  of  the  acoustic  centre  of  speech  which,  as  a  rule,  functions 
in  concert  with  the  visual  centre  in  men  accustomed  to  reading,  and  some- 
times it  causes  also  a  significant  disturbance  of  the  kinsesthetic  centre  of 
articulation.  This  disturbance  is  more  severe  the  higher  the  degree  of 
evolution  attained  by  the  visual  word-centre. 

S oilier  adopts  the  hypothesis  of  Flechsig  to  explain  the  mechanism  of 
language.  The  auditory  and  visual  word-images  would  not  reside,  as  it  were, 
in  the  centres  of  reception  but  in  other  localities.  These  centres  would  really 
rank  as  associative  centres,  and  destruction  of  them  would  produce  word- 
deafness  and  word-blindness,  not  because  the  formative  organ  of  the  linguistic 
images  would  be  destroyed,  but,  rather,  on  account  of  destruction  of  the  organ 
which  has  the  function  of  transmitting  the  vibrations  that  determine  a  par- 
ticular state  corresponding  to  the  excitation,  external  or  internal.  Reference 
has  already  been  made  (Chapters  I.  and  II.)  to  the  obscure  nature  of  this 
hypothesis,  which  is  not  supported  by  any  facts  which  would  give  it  a  claim 
to  probability. 

As  explained  in  Chapter  I.,  evolution  of  language  has  necessarily  been 
accompanied  by  development  of  the  sensory  areas.  The  auditory  (temporal) 
field  extends  its  boundaries  and  develops  an  area  which,  though  still  auditory, 
is  yet  concerned  particularly  with  the  construction  of  acoustic  verbal  images, 
or  word-symbols,  of  all  the  thought  that  has  been  gradually  elaborated  in 
the  other  sensory  areas,  with  material  derived  from  the  external  world.  It 
comprises  a  good  part  of  the  middle  and  posterior  sections  of  the  first  and 
second  temporal  convolutions.  Similarly,  the  visual  area  extends  forwards, 
in  front  of  the  visuo-psychic  area,  for  the  construction  of  graphic  word- 
symbols  of  the  images  of  objects  and  features  that  have  been  elaborated  and 
conserved  in  the  various  sensory  areas,  including  that  of  the  acoustic  word- 
symbols.  Thus  it  comes  about  that  men  who  are  near  one  another  can 
understand  each  other  by  speaking,  whilst  men  far  removed  from  one  another 
can  understand  each  other  by  writing.  So,  too,  the  patrimony  of  one 
generation  or  epoch  becomes  transmitted  to  succeeding  generations,  to 
become  material  of  transformation  in  the  renewed  mental  mechanisms  of 
those  who  come  after,  continuing  the  process  of  evolution.  Every  simple 
image,  every  complex  image,  every  synthesis  of  thoughts,  on  a  progressively 
complicated  scale,  becomes  clothed  in  a  linguistic,  sensible  form,  and  is  thus 


INTELLIGENCE  AND  LANGUAGE  241 

rendered  capable  of  being  transmitted  to  other  beings.  The  cerebral  mantle 
becomes  evolved  and  perfected  with  the  transformation  of  old  and  the 
establishment  of  new  workshops  which  every  day  accomplish  an  increased 
amount  of  work,  owing  to  the  more  plentiful  and  varied  material  supplied 
to  them,  in  consequence  of  the  growth  of  interhuman  relations.  It  is  not 
the  case,  as  Flechsig  thinks,  that  the  language-areas  thus  become  the  organs 
of  transformation  of  external  and  internal  realities  because,  correctly  speak- 
ing, realities  take  their  form  in  the  sensory  areas.  What  happens  is  that, 
in  the  linguistic  mechanisms,  facts  become  connected  together  into  a  logical 
series,  for  the  purposes  of  human  interchange  of  thought.  All  external  and 
internal  facts  pass  through  the  auditory  field  of  language,  and  are  thence 
transmitted  to  other  men  in  a  sensible  form  and  in  logical  relations,  in  the 
guise  of  acoustico-motor-  and  visuo-graphic  verbal  symbols.  When  the 
cortical  organs  of  speech  suffer  any  severe  injury  (well-known  pathological 
processes)  the  whole  mental  capital  becomes  interdicted  and  its  natural 
movement  hindered.  This  capital,  or,  in  other  words,  the  accumulation 
of  images  which  reflect  reality,  remains  intact  in  the  sensory  areas  but  is  not 
utilisable,  because  there  are  lacking  not  only  the  names  which  symbolise 
them  but  the  material  means  of  conjunction  necessary  for  formulating 
complex  judgments,  in  logical  series.  The  aphasic,  if  not  markedly  hemiplegic, 
rises  in  the  morning  like  any  other  man,  puts  on  his  clothes  (he  recognises 
them  and  their  use),  goes  to  the  lavatory,  washes  himself,  dresses  himself, 
makes  his  way  to  the  dining-room  and  takes  his  breakfast.  If  the  coffee  is 
bitter  he  recalls  the  image  of  sugar  and  procures  some.  He  thus  formulates 
immediate  judgments — the  coffee  is  bitter,  sugar  sweetens  coffee.  Judgments 
of  this  kind  are  possible  to  this  man,  just  as  they  are  to  a  dog.  To  formulate 
them  it  is  quite  sufficient  that  he  have  the  images  of  the  things  connected 
with  the  immediate  sensation  of  sweetness  or  bitterness.  As,  however,  he 
does  not  possess  the  word-symbols  of  the  coffee,  the  sugar  and  the  persons, 
and,  what  is  more  important,  the  word-symbols  of  the  relations  between 
the  things  or  their  images  (verbs  and  their  inflexions),  it  is  quite  impossible 
for  him  to  say  :  "  The  coffee  is  bitter.  Bring  me  some  sugar."  If,  at  one 
time  or  another  in  his  life,  he  has  taken  coffee  with  a  family  in  Constantinople, 
he  may  remember  the  aroma  of  that  coffee  and  compare  it  with  what  he  gets 
at  home  (the  centres  of  taste,  smell  and  sight  are  perfectly  capable  of  furnish- 
ing these  particular  images  and  records)  ;  but  he  cannot  engage  in  conversa- 
tion on  this  subject ;  he  cannot  formulate  such  a  simple  sentence  as  :  "  The 
coffee  at  Constantinople  was  very  fragrant,"  because  he  lacks  not  only  the 
words  that  express  names  and  qualities  (predicates)  but  also  those  that 
express  relations  between  objects  and  relations  as  to  time  (verbs).  The 
intellectual  material  (the  concrete  notions)  is  preserved  but  remains  inactive 
and  interdicted.  This  is  a  variety  of  dementia  the  feature  of  which  the  author 
has  several  times  sought  to  differentiate.  In  1887  *  he  had  occasion  to 

1  Bianchi.     "  Un  caso  di  sordita  verbale.     II  metodo  pedagogico  nella  cura 
della  stessa."     Riv.  sper.  di  Fren.     1887. 

Q 


242  THE  MECHANISM  OF  THE  BRAIN 

write :  "  Unless  I  am  mistaken  in  my  study  of  this  patient,  there  is  good 
ground  for  advancing  the  opinion  that  in  severe  word-deafness  the  intellect 
is  only  potentially  sound  inasmuch  as  there  is  no  damage  to  its  material 
constitution,  such  as  we  find  in  primary  or  in  terminal  dementias  :  its  con- 
stituent elements,  indefinite  as  they  are,  no  longer  awaken  states  of  con- 
sciousness, but  remain  buried  in  the  subconscious  ;  from  this  they  may  be 
evoked  into  the  field  of  consciousness  whenever  this  is  reached  by  the  corre- 
sponding sensible  word-symbol  with  all  its  associative  relations."  In  much 
more  recent  times  various  hypotheses  as  to  the  relations  between  intellect 
and  language  have  been  put  forward,  but  they  are  not  all  clear  or  convincing. 
Dejerine,1  e.g.,  maintains  that  the  act  of  thinking  may  be  effected  in  two 
ways — either  with  the  images  of  things  or  with  the  images  of  words  (internal 
language).  Even  this  conception  of  Dejerine,  however,  does  not  meet  the 
case  ;  it  is  not  at  all  complete.  Such  thought  as  consists  of  the  images  of 
objects  alone  is  a  very  simple,  rudimentary  form  of  thought,  and  is  only 
possible  when  the  word-symbols  are  not  reproducible.  It  is  only  by  the  aid 
of  word-symbols  that  thought  flows  freely  through  all  the  paths  and  follows 
all  the  rules  of  logic.  Dupre  is  more  exact  when  he  says  that  the  two  syn- 
dromes, dementia  and  aphasia,  are  two  intellectual  deficits,  but  whilst  the 
former  concerns  the  operations  of  the  mind  in  general  (memory,  association 
of  ideas,  reasoning,  affective  or  voluntary  reactions) ,  the  latter  has  to  do  with 
the  process  of  verbal  symbolism,  compromising  the  existence  and  play  of  the 
mnemonic  materials.2 

We  have  already  mentioned  that  the  concrete  images  of  objects  are  formed 
in  their  own  respective  seats,  independently  of  the  verbal  images.  This 
view  has  been  excessively  and  even  erroneously  generalised.  Mingazzini 
and  Seglas  3  hold  that  the  word  is  an  auxiliary  of  the  image  of  the  object 
(of  the  idea,  says  Seglas).  The  latter  author  writes  :  "  The  idea  may  exist 
without  the  word."  One  might  agree  with  this  view  if  we  limit  the  significa- 
tion of  "  ideas  "  to  the  concrete  images  of  objects.  It  is  to  be  observed, 
however,  that  abstract  or  general  ideas,  no  matter  what  Dejerine  and  Seglas 
may  think,  cannot  be  represented  in  consciousness,  unless  fused  with  the 
verbal  symbol.  Sufficient  has  already  been  said  on  this  subject  in  the 
preceding  chapters,  but  it  may  be  worth  while  to  give  an  example.  I  can 
recall  all  the  visual  and  auditory  (phonetic)  images  of  the  Parliament  Hall 
and  the  physiognomies  of  my  colleagues,  their  attitudes  when  they  speak, 
the  calls  of  the  President,  the  written  sheets  with  the  orders  of  the  day, 
as  things  seen ;  but  I  cannot  represent  to  myself  the  content  of  political 
thought  of  my  colleagues  which  is  made  up  of  word-abstractions.  If  there 
fail  me  the  words  "  parliament,"  "  politics,"  "  government,"  "  presidency," 
etc.,  and  the  political  syntheses  of  the  parliamentary  debate,  which  is  en- 
tirely composed  of  words,  the  material  belonging  to  the  visual  images 
remains  almost  inactive.  One  has  also  to  take  into  consideration  the 

1  Dejerine.     Pathologic  generate  de  Bouchard.     Semeiologie,  tome  v. 

2  E.  Dupre.      "  Revue  policlinique  des  demences."     Bulletin  medical.      1907. 

3  Seglas.     Lemons  cliniques  sur  les  maladies  mentales  et  nerveuses. 


INTELLIGENCE  AND  LANGUAGE  243 

great  value  of  verbs  and  their  inflexions  in  the  logical  process  of 
thought. 

Without  verbs  immediate  judgments  are  possible,  but  not  the  formation 
of  phrases  and  sentences  immediately  bound  up  with  the  logical  development 
of  thought.  In  the  aphasic,  what  we  call  a  train  of  thought  is  interfered 
with  in  its  motion  towards  the  focal  point  of  consciousness  so  that  it  cannot 
reach  it  in  logical  connection  with  other  thoughts,  and  hence  there  is  no  process 
of  fusion  into  general  ideas. 

We  have  learned  that  images  of  objects  are  formed  before  images  of 
words,  as  can  be  observed  in  infants,  but,  in  the  process  of  evolution  of  intel- 
lect, these  images  become  blended  with  the  word-symbols,  and  subsequently 
the  word-symbols  are  conjoined  with  one  another  for  the  construction 
of  phrases,  when  we  get  inflexion  of  words  and  the  use  of  conjunctions. 
When  once  the  capital  of  cognitions  is  greatly  increased  and  associative 
relations  are  established  between  its  component  parts,  when  the  mind 
embraces  wider  dominions,  there  commences  the  formation  of  sentences, 
and,  later,  we  get  narration — i.e.  a  series  of  sentences  conjoined  with  one 
another  around  a  central  theme,  which  is  detained  in  the  focal  point  of 
consciousness.  In  this  case  the  images  of  things  remain  on  the  first  level, 
whilst  around  the  theme  there  flow,  from  the  different  cortical  fields,  all  the 
notions  that  have  a  bearing  upon  it  and  all  the  intellectual  creations  of  which 
the  mind,  with  its  imaginative  power,  is  capable,  all  in  linguistic  form.  It 
is  in  the  form  of  words  that  they  cross  the  focal  point  of  consciousness  and 
contribute  to  the  formation  of  thought.  If  we  take  the  case  of  the  parlia- 
mentary aphasic  one  may  unhesitatingly  affirm  that  he,  being  unable  to 
recall  nouns,  predicates,  and  a  very  large  number  of  verbs  with  their  relative 
inflexions,  will  not  be  able  to  remember  (reproduce)  the  content  of  the 
speeches  made  by  his  colleagues  in  the  House  when  he  was  sound  and  well 
and  able  to  participate  in  the  parliamentary  debates — speeches  made  up  of 
abstract  concepts,  names  of  persons,  concrete  and  general  ideas,  and  of  verbs. 
In  such  a  case,  what  remains  of  intelligence  ?  The  interdicted  material, 
and  the  images  of  the  things  by  means  of  which  immediate  judgments  may  be 
formulated.  The  dog  which  displays  exceeding  joy  when  he  sees  his  master 
put  on  his  hunting  boots  and  take  up  his  gun  may  picture  to  himself  the  hare, 
the  bird,  the  moor,  the  gun-shots,  the  dead  game,  etc.,  by  a  process  of 
imagination  (Romanes). 

The  judgments  formulated  by  monkeys  are  much  more  complex,  as  in 
the  case  of  the  animal,  mentioned  by  the  writer,  which,  after  being  admonished, 
hid  behind  the  couch  and  peeped  out  from  time  to  time,  when  the  author 
moved  to  another  spot  or  had  his  attention  fully  occupied,  so  that  it  might 
seize  an  opportunity  to  jump  upon  the  table  and  furtively  snatch  away  the 
cherries  of  which  it  was  fond. 

In  the  aphasic  patient  the  position  of  the  intellectual  process  is  much 
more  serious  because,  whilst  in  the  higher  mammals  the  mechanism  of  the 
judgments  is  very  simple  owing  to  the  absence  of  linguistic  overlapping,  in 
man,  on  the  other  hand,  with  his  complicated  mechanism  interposed  between 


244  THE  MECHANISM  OF  THE  BKAIN 

the  images  of  objects  and  all  the  forms  of  expression  and  of  action,  the  latter 
lose  that  expressive  fidelity  which  they  derived,  in  varying  proportions  in 
different  men  (heredity,  education),  from  the  greater  or  less  precision  of  the 
word- symbols.  For  this  reason  lesions  affecting  the  cortical  or  subcortical 
areas  of  speech  cause  a  conspicuous  mental  disorder.  Thus,  too,  is  explained 
the  great  frequency  of  amimia  and  apraxia. 

In  the  case  of  single  ideas  of  objects  and  immediate  reactions,  such  as  we 
find  in  the  higher  mammals,  in  infants,  and  even  in  normal  man,  there  is  some 
room  for  Seglas'  notion  (loc.  cit.)  that  the  image  of  the  word  is  an  auxiliary 
of  the  image  of  the  object,  or  Mingazzini's  l  notion  that  internal  speech 
(representations  of  verbal  images)  is  of  great  utility  in  the  elaboration  of 
concepts,  although  the  association  between  ideas  and  verbal  images  is  not 
indispensable.  This  would  mean  that  both  may  have  free  course,  independent 
of  each  other,  without  thought  as  a  whole  suffering  thereby.  There  is  here 
an  evident  lack  of  distinction  between  single  images  with  simple  reactions 
on  the  one  hand  and  connected  thought  on  the  other,  between  single  images 
and  regular  trains  of  co-ordinated  ideas,  characteristic  of  evolved  human 
intellect,  as  manifested  in  talk  and  conduct. 

This  confusion  of  thought  with  images  was  and  is  the  cause  of  many 
euphemisms  2  which  tend  to  hinder  the  correct  interpretation  of  the  facts. 
Some  estimable  neurologists  unknowingly  participate  in  the  Platonic  doctrine, 
maintained  by  realists  and  certain  metaphysicians,  to  the  effect  that  ideas 
are  so  many  realities  existing  throughout  eternity,  that  they  emanate  from 
God  and  are  found  in  the  world  outside  of  us.  Having  made  this  allusion 
to  doctrines  of  ancient  time,  the  writer  professes  his  partiality  for  the  ideas 
of  Aristotle  who  taught  the  peripatetics  that  words  are  signs  of  the  concepts, 
which  latter  are  derived  from  experience.  More  definite,  though  rather 
original,  is  the  notion  of  Pierre  Marie,  who  denies  the  existence  of  images 
of  language  and  maintains  that  there  do  not  exist  any  word-images  either 
auditory,  visual  or  motor.  In  the  words  of  his  pupil  Moutier3  :  "  'Verbal 
images  '  are  words  void  of  sense,  they  are  metaphysical  things  which  should 
be  expurged  from  our  vocabulary. "  If  this  were  true  we  should  be  compelled 
to  take  refuge  in  the  doctrine  of  Plato,  or  to  entrust  all  these  distinctions 
between  images  of  things  and  verbal  images  of  things  to  the  science  of 
physics,  which  might  invoke  the  perennial  motion  and  indestructibility  of 
the  electrons. 

Any  attempt  to  simplify  the  problems  of  mental  life  by  the  construction 
of  diagrams  is  apt  to  be  dangerous  and  to  lead  us  into  grave  error.  Never- 
theless, the  diagrams  the  writer  here  puts  forward  may  serve  to  give  a  clearer 
understanding  of  the  mechanism  of  thought  and  its  reflexes  in  action  and  in 
speech.  Let  us  consider  the  representation  of  the  image  of  an  object  e.#. 
an  orange.  The  complete  image  is  composed  of  several  images  formed  in 

1  Mingazzini.     Lezioni  di  anatomia  clinica  dei  centri  nervosi.     1913. 

2  Brissot,  G.     Aphasie  dans  ses  rapports  avec  la  demence.     1912. 

3  Moutier.     Aphasie  de  Broca.     Paris,  1908. 


INTELLIGENCE  AND  LANGUAGE  245 

different  cortical  fields :  the  visual,  reflecting  the  form,  size  and  colour,  in 
the  occipital  lobe  ;  the  tactile  and  thermic,  in  the  post-Kolandic  convolution  ; 
the  olfactory,  in  the  limbic  lobe ;  and  the  gustatory  in  the  temporal  pole. 
These  four  images  reawaken  one  another,  in  a  reciprocal  fashion,  in  their 
respective  cortical  areas,  by  means  of  association  fibres.  In  the  representa- 
tion, one  image  will  prevail  over  the  others,  according  as  particular  individuals 
(for  various  reasons,  which  it  is  needless  to  mention  here)  have  developed  one 
of  the  four  senses  to  a  greater  extent  than  the  others,  and,  therefore,  one  of 
the  organs  concerned  in  the  production  of  these  images.  All  four  images 


Diagram  A 

SV.  Luminous  image.— VM.  Senso-motor  elements  necessary  for  the  formation 
of  the  visual  image.— V,  O,  T,  G.  Visual,  olfactory,  tactile  and  gustatory 
images. — M.  Motor  field  for  movements  of  advance  and  retreat 

together  give  the  concrete  image  of  the  orange.  In  the  case  of  the  infant, 
there  are  no  images  other  than  these,  and  we  find  them  accompanied  by  a 
tendency  to  draw  nigh  or,  perhaps,  a  movement  of  prehension. 

Later  on,  the  concrete  image,  or  this  group  of  images,  becomes  translated 
into  the  verbal  symbol,  the  word  "  orange,"  which  represents  a  fusion  or 
synthesis  of  all  the  pre-existing  memory-traces. 

When  we  see,  or  picture  to  ourselves,  an  orange,  all  the  four  images, 
0,  T,V,  G,  with  the  respective  elementary  components  SV,  VM,  are  awakened, 
and  all  tend  to  cross  the  threshold  of  consciousness.  As  the  orange  is  a 
pleasing  thing,  a  charge  is  determined  in  the  motor  area,  accompanied  by  a 
tendency  to  approach  and  take  the  orange.  The  images  0,  T,  V,  G,  acting 
through  the  mechanism  of  emotion  and  desire  (about  which  we  will  talk 
elsewhere),  arouse  the  image  of  the  movement  or  movements  necessary  to 
reach  and  take  it.  To  avoid  complicating  the  diagram  the  circle  M  is  made 


246 


THE  MECHANISM  OF  THE  BRAIN 


to  represent  the  twofold  physiological  fact — the  image  of  the  movements 
and  the  motor  discharge,  the  latter  being  given  off  from  the  motor  centre  and 
modelled  in  turn  upon  the  images  of  the  movements. 

In  the  higher  mammals  and  in  the  infant,  M  is  excited  directly  by  0,  T,  V,  G 


Diagram  B 

SV,  VM,  O,  T,  V,  G.  All  as  in  preceding  diagram.— M.  Motor  field  for  move- 
ments  of  approach  animated  by  all  or  by  one  of  the  fields  of  the  separate 
sensory  images  of  the  orange,  O,  T,  V,  G. — AM.  Represents  the  field  of 
the  acoustic  and  motor  images  of  the  word  "orange"  (shown  as  a  single 
field  in  the  diagram  to  facilitate  comprehension  of  the  mechanism,  and  to 
avoid  complicating  the  diagram  too  much). — S.  Cortical  and  subcortical 
anatomical  field  for  movements  necessary  in  the  articulation  of  the  word. 
Note  that  the  new  fields  all  assume  associative  relations  with  one  another, 
and  with  the  pre-existing 

together,  or  it  may  be  by  one  only  of  these,  in  this  case  the  most  strongly 
representative,  or  that  most  intimately  connected  with  emotion  and  desire. 
When  language  is  developed  the  verbal  symbol  also  assists  in  determining 
movements  of  locomotion  and  prehension.  The  mechanism  is  now  more 
complicated  (Diagram*  B) .  The  representation  of  the  verbal  image  does  not 


INTELLIGENCE  AND  LANGUAGE  247 

really  increase  the  impulse  to  approach,  which  rather  arises  from  emotion 
(desire),  but  it  is  certainly  a  positive  element  which  reinforces  the  image  of 
the  object  and  the  determinism  to  advance  or  retire. 

The  separate  images  of  the  orange  become  inevitably  associated  with  the 
verbal  symbol,  and  all  together  arouse  the  function  of  M.  At  the  same  time, 
or  a  little  later  on,  the  acoustic  verbal  symbol  in  the  infant  becomes  translated 
into  the  articulate  word,  a  close  association  being  established  between  the 
acoustic  image  and  the  motor  image  of  the  word.  This  new  organ,  which 
comes  to  be  interposed  in  the  mechanism,  is  represented  by  M  placed  in  the 
same  circle  along  with  A,  for  simplicity's  sake,  in  Diagram  B.  Subsequently, 
the  human  subject  learns  to  read  and  write  and  so  makes  use  not  only  of  the 
acoustico -motor  verbal  symbol  but  also  of  the  visual  verbal  symbol,  thus 
adding  still  another  organ  to  the  mechanism,  which  is  rather  imperfectly 
represented  in  Diagram  C. 

All  this  work  takes  place  in  the  sensory  mantle,  which  includes  the  cortical 
fields  of  language  or,  in  other  words,  all  that  part  of  the  hemisphere  lying 
posterior  to  the  fissure  of  Kolando. 

By  degrees  there  is  formed  the  abstract  conception  of  citrus,  which  com- 
prises a  certain 'number  of  horticultural  products  which  are  very  similar  to 
one  another,  and  as  time  goes  on  another  concept,  even  more  general,  is 
arrived  at,  such  as  that  of  fruit.  The  word  citrus  synthetises  as  many  different 
images  similar  to  that  of  the  orange  as  there  are  varieties  of  citrus -fruits,  and 
sets  in  vibration  all  the  corresponding  fields,  the  respective  images  of  which 
become  directed  towards  the  threshold  of  consciousness,  although  they  may 
not  actually  cross  it. 

Suppose,  now,  that  the  modern  evolved  man  studies  to  increase  the  size 
and  aroma  of  the  orange  for  commercial  purposes.  He  is  obliged  to  construct 
a  series  of  judgments  of  similarities,  analogies  and  differences  between  the 
known  varieties  of  oranges,  and  to  inquire  into  the  chemical  constitution  of 
the  soils,  the  influence  of  the  climates,  the  exposure  of  the  fields,  etc.  He 
obtains  information'  regarding  the  markets  on  which  he  intends  to  place  his 
goods  and  establishes  the  conditions  necessary  to  attain  his  object.  He 
calculates  the  various  problems  and  then  inquires  into  the  means  of  transport, 
and  gives  attention  to  the  question  of  preservation.  All  this  work  implies  : 
(1)  the  possession  of  a  considerable  knowledge  of  agriculture,  and  hence  of 
physics,  chemistry  and  botany,  and  the  power  of  increasing  this  by  extending 
the  inquiry  into  new  fields  (the  experience  of  others  which  he  obtains  by 
means  of  reading  and  by  verbal  communications)  ;  (2)  another  series  of  cogni- 
tions concerning  trade  in  oranges,  the  uses  of  oranges,  and  the  tastes  and 
habits  of  the  various  peoples  who  cannot  produce  these  fruits,  so  as  to  select 
the  best  markets  ;  (3)  a  third  series  of  cognitions  relating  to  methods  of 
preservation  during  long  or  short  transits  by  sea  and  land  (all  these  cognitions 
are  really  series  of  mental  syntheses,  logically  drawn  from  experience  and 
imagination,  and  disposed  in  memory  in  accordance  with  personal  observa- 
tions and  the  observations  of  other  people  ;  (4)  a  capacity  to  detain  the  argu- 
ment in  consciousness  or,  in  other  words,  the  power  of  voluntary  attention  ; 


248 


THE  MECHANISM  OF  THE  BRAIN 


(5)  a  power  to  evoke  and  select  cognitions  stored,  it  may  be,  a  considerable 
length  of  time,  representing  a  long  and  varied  experience  in  accordance  with 
altered  circumstances  of  time,  place  and  persons  ;  (6)  a  capacity  to  formulate 
ultimate  logical  conclusions — i.e.  to  form  a  synthesis  of  syntheses as  mani- 
fested in  deliberation,  determining  action  and  conduct.  The  latter  will  be 
more  or  less  successful,  according  to  the  capital  of  cognitions,  the  power  of 
evocation  and  the  associative  and  selective  capacity,  which  together  give 
rise  to  a  series  of  actions  best  calculated  to  attain  the  object  in  view. 


Diagram  C 

The  diagram  is  the  same  as  the  preceding  except  for  the  fact  that  the  primary 
fields,  SV,  VAT,  are  not  represented,  whilst  there  is  added  a  new  field,  VV, 
in  those  who  have  learned  to  read.  VV,  the  graphical  visual  field,  may 
also  act  directly  on  S 

All  this  immense  work  becomes  translated  into  three  words :  citrus- 
cultivation,  citrus-trade. 

When  we  think  of  citrus -cultivation  and  trade  in  citrus  fruits,  there 
vibrates,  more  or  less,  throughout  the  whole  brain,  all  that  incalculable 
number  of  ideas  represented  by  the  three  words  in  intensely  synthetic 
forms  which,  in  turn,  are  composed  of  other  syntheses,  no  doubt  less 
complicated  but  all  inseparably  combined  with  the  respective  words. 

This  last  part  of  the  cerebral  work  is  performed  with  the  aid  of  another 
extensive  cortical  field,  that  of  the  frontal  lobes  which  are  intimately  con- 
nected with  all  the  different  sensory  and  linguistic  fields.  The  latter  furnish 
all  the  concrete  images  and  the  symbolic  (linguistic)  elements  which  allow  of 
reasoning  in  the  form  of  a  complex  train  of  thoughts,  involving  a  long  and 


INTELLIGENCE  AND  LANGUAGE 


249 


logical  process  of  development.  The  frontal  field  conceives  the  theme  in  a 
synthetic  manner,  detains  it  in  consciousness  and  unfolds  it  by  re-evoking 
cognitions  relating  thereto  ;  it  exercises  the  power  of  selection,  utilising  the 
immense  capital  of  concrete  images  and  words,  maintaining  a  logical  con- 
nection between  the  various  parts  that  compose  the  vast  design  and  arriving 


Diagram  D 

This  diagram  shows  the  field  of  the  mental  syntheses  more  fully  than  the  preceding.  I  is  the  organ 
on  which  all  the  products  of  the  other  sensory  and  motor  fields  converge,  for  the  construction  of 
syntheses  depending  upon  the  power  of  re-evocation  of  the  single  images  and  groups  of  images 

at  a  conclusion  which  becomes  translated  into  a  logical  series  of  actions  well 
adapted  to  achieve  the  end  in  view.  So  complicated  is  this  mechanism  that 
no  diagram  can  give  more  than  the  faintest  idea  of  it.  In  Diagram  D  there 
is  inserted  a  circle  which  is  not  present  in  the  preceding  diagram.  It  is 
intended  to  represent,  in  a  diagrammatic  and  circumscribed  manner,  what 
cannot  really  be  translated  in  a  sensible  form — the  contemporary  and 
successive  operations  of  millions  of  cell-groups  scattered  throughout  the 
cerebral  mantle. 


250          .  THE  MECHANISM  OF  THE  BRAIN 

"  I  "  symbolises  the  frontal  lobes — the  organs  of  the  ontogenetic  and 
phylogenetic  experience  of  the  consciousness,  nourished  by  records  of  the 
effects  of  previous  actions,  which  undergo  useful  variations  of  adaptation ; 
they  are  consequently,  as  already  indicated,  evocative  and  directive  organs 
of  thought  and  of  action  related  to  the  end  in  view. 

Experiments  on  the  higher  mammals  and  clinical  observations  of  men 
who  have  suffered  extensive  lesions  of  the  frontal  lobes  (foci,  wounds,  tumours) 
bring  into  evidence  two  orders  of  facts — (a)  the  sensory  cortical  field  continues 
to  function  normally  so  that  individual  perceptions  are  normal ;  (6)  language 
and  the  simple  reactions — i.e.  those  which  do  not  involve  any  extensive 
reasoning — remain  normal.  The  whole  cycle  of  mental  life  in  these  cases  is 
manifested  in  isolated  actions  to  which  the  separate  impressions  give  rise. 
There  is  an  evident  absence  of  mental  co-ordination,  whilst  the  representations 
are  more  or  less  isolated.  There  is  nothing  to  indicate  a  true  movement  of 
thought,  a  co-ordinated  process  manifesting  itself  in  speech  and  action,  a 
preconceived  objective  and  a  capacity  to  fix  this  objective  in  consciousness 
and  to  select  the  requisite  material  from  the  mental  capital. 

The  behaviour  of  monkeys  that  have  suffered  mutilation  of  the  frontal 
lobes  is  strongly  indicative  of  a  suppression  of  all  the  manifestations  of 
initiative  and  curiosity.  This  goes  to  prove  that  the  experiment  has  resulted 
in  suppression  of  the  imaginative  capacity,  the  evocative  power  and  the 
determinism  to  think.  The  syndrome  is  complicated  by  irrational  fear, 
errors  of  judgments,  indifference  towards  persons  and  things,  by  a  tendency 
to  collect  garbage  and  useless  objects  (like  some  idiots  and  dements)  and  by 
tics.  Perceptive  indifference,  entire  absence  of  initiative,  lack  of  objective, 
incapacity  to  pursue  a  logical  train  of  thought  and  pronounced  emotional 
episodes  (fear,  anger,  sometimes  aggressiveness,  leading  to  emotional  reaction) 
are  common  features  in  the  life  of  imbeciles.  All  this  train  of  symptoms  is 
fairly  indicative  of  the  function  of  the  frontal  lobes. 

Anyone  who  has  had  an  opportunity  of  examining  a  large  number  of 
patients  suffering  from  the  disturbances  referred  to,  disturbances  which  ex- 
hibit themselves  in  all  degrees  of  alterations  of  character,  cannot  have  failed 
to  be  impressed  by  the  fact  that  in  every  aspect  of  their  intelligence,  either 
in  relation  to  the  physical  or  to  the  social  environment,  the  most  prominent 
feature  has  been  perceptive  insufficiency  in  the  sense  that  they  are  attracted 
only  by  the  strongest  stimuli,  whilst  their  perceptive  capacity  fails  to  gather 
a  number  of  the  more  specific  features  which  are  necessary  for  the  complete 
cognition  of  objects  and  for  the  differentiation  of  one  object  from  another 
that  is  similar  or  analogous.  The  idiot,  like  the  mutilated  monkey,  takes  a 
piece  of  chalk  and,  mistaking  it  for  sugar,  puts  it  in  his  mouth  and  does  not 
decide  to  spit  it  out  when  he  fails  to  detect  the  sweet  taste  of  sugar,  or,  if  he 
does  reject  it,  does  so  grudgingly.  One  can  easily  play  tricks  upon  him  by 
offering  him  something  resembling  an  object  for  which  he  has  a  predilection, 
and  time  after  time  he  will  obstinately  attempt  to  get  possession  of  it.  Not 
only  does  he  fail  to  perceive  a  number  of  features  that  are  always  detected 


INTELLIGENCE   AND   LANGUAGE  251 

by  a  normal  person,  but  he  is  torpid  and  slow  in  his  movements  and  shows  an 
indifference  to  both  persons  and  objects.  He  gathers  up  from  the  ground 
all  sorts  of  useless  articles,  even  filth,  and  puts  them  in  his  mouth ;  he  will 
stop  for  a  long  time,  without  obvious  reason,  over  a  spot,  a  rag,  or  a  piece 
of  paper.  Some  idiots  eat  everything  that  is  given  to  them.  The  absence 
of  choice  is  frequent  amongst  them.  Nearly  all  are  easily  frightened  ;  they 
do  not  distinguish  a  pretended  threat  from  a  real  danger,  nor  do  they  under- 
stand ridicule  or  appreciate  the  pungency  of  irony.  They  are  unsociable 
and  may  or  may  not  show  an  attachment  to  the  person  who  gives  them  food 
and  takes  care  of  them.  Rarely  do  they  exhibit  any  spontaneous  activity. 
They  never  take  the  initiative  in  talking,  or  even  in  some  simple  action ; 
they  follow  no  preconceived  plan,  not  even  when,  as  in  the  less  pronounced 
imbeciles,  speech  is  fairly  well  developed.  They  are  egoistic  and  impulsive 
and  often  exhibit  tics. 

Their  attention  is  weak  and  cannot  be  fixed  on  anything.  They  touch 
many  objects  one  after  another,  and  these  they  often  break  without  exhibit- 
ing anything  of  that  curiosity  which  is  truly  attentive  and  so  characteristic 
of  any  normal  child.  Their  memory  is  unfaithful  and  their  action  incon- 
clusive, as  also  the  content  of  their  thought,  which  is  evanescent.  They 
hardly  ever  make  use  of  past  experience  (even  in  the  case  of  those  few  who 
possess  a  partial  memory  that  is  sometimes  very  remarkable).  Association 
is  very  poor.  The  mental  complexes  are  of  surprising  simplicity.  They 
keep  apart  from  others. 

There  can  be  no  doubt  that,  just  as  the  degree  of  mental  insufficiency  in 
the  case  of  idiots  is  proportionate  to  the  degree  of  subevolution  of  the  layer 
of  pyramidal  cells  (small  an$  large),  so,  in  cases  of  pathological  or  traumatic 
lesion  of  the  frontal  lobes  and  of  experimental  injury  (in  monkeys),  the  mental 
defect  is  proportionate  to  the  extent  of  the  lesion,  provided  it  be  bilateral. 


APPENDIX  TO  CHAPTER  VIII 

Logic 

IN  a  previous  chapter  we  have  mentioned  the  fact  that  in  the  perceptive 
process  is  included  a  logical  factor,  inasmuch  as  every  perception  contains 
elements  of  judgment,  and  these  reflect  the  reality  perceived.  The  conclusion 
arrived  at  as  the  result  of  a  perception  becomes  combined  with  the  residual 
train  of  previous  experiences  of  identical,  analogous  or  different  natures, 
also  with  the  experience  of  the  successive  reactions  provoked  by  the  series  of 
similar  or  analogous  percepts,  and  with  all  the  various  judgments  derived 
from  notions  with  which  the  actual  fact  perceived  has  associative  relations 
reflecting  external  reality  or  intellectual  and  emotional  reality.  Logic,  as  a 
science,  cannot  be  considered  outside  of  the  data  and  natural  process  of 
experience,  based  on  memory  and  association.  Individual  or  collective 
experience  is  wholly  constructed  of  mnemonic  residua,  and  it  furnishes  the 
content  of  phantasy  (or  imagination).  Phantasy  transports  the  conscious- 
ness into  an  analogous  or  different  situation,  in  the  future,  a  situation  which 
is  nothing  more  than  a  conclusion  drawn  from  past  experience  and  projected 
into  the  future,  determining  integrative  or  defensive  attitudes  or  new 
creations.  Foresight  is  the  outcome  of  a  logical  process  based  on  experience 
(memory,  association  and  phantasy).  The  perceptive  process  furnishes  an 
objective  reality  which  becomes  thought ;  the  logical  process  reflects  the 
association  of  objective  realities  in  their  relations  of  simultaneity,  similarity, 
contrast  and  succession,  in  relation  to  the  self  which  feels  these  realities, 
categorising  and  classifying  them  and  reacting  accordingly.  It  is  from  these 
relations  that  experience  arises.  Experience  is  essentially  the  outcome  of 
series  of  reactions  of  the  self,  from  the  most  simple  to  the  most  complex, 
either  integrative  or  disintegrative,  attractive  or  repulsive. 

Logic,  according  to  an  old  conception,  is  the  science  which  examines, 
defines  and  concretes  the  condition  and  the  procedure  of  exact  knowing  and 
correct  thinking,  laying  down  rules  and  laws  which  the  intellectual  operations 
must  obey,  if  they  are  to  be  regarded  as  legitimate.  It  is  unnecessary  here  to 
make  acquaintance  with,  these  laws.  It  is  of  much  greater  importance  that  we 
should  recognise  clearly  the  reality  itself,  as  it  is  revealed  to  us  by  experience. 

Modern  psychology  seeks  to  discover  and  learn  the  laws  of  thought  and 
the  origin  of  the  nexus  between  the  parts  of  speech,  not  to  lay  down  aprior- 
istic  laws  of  concrete  reasoning.  It  is  its  business  to  examine  the  logical 
process  of  thought  and  of  conduct  in  relation  to  the  evolution  of  knowledge 
through  the  perceptive  and  reactive  experience  of  life,  and  through  the 
development  of  the  capital  of  language,  which  is  an  essential  condition  of 
the  logical  process  of  speech. 

252 


APPENDIX  TO  CHAPTER  VIII  253 

In  this  respect  the  evolution  of  logic  coincides  with  the  evolution  of 
language.  We  must  recognise  an  immediate  logic  corresponding  to  immediate 
judgments  and  manifesting  itself  in  actions  directed  by  the  hedonistic  law  of 
life.  Biophylactic  coherence  of  conduct  is  logical  but  does  not  necessarily 
require  language.  My  dog,  e.g.,  has  learned  from  experience  in  the  dining- 
room  that  the  same  diner  does  not  offer  him  two  pieces  of  meat  one  im- 
mediately after  the  other,  and  so,  as  soon  as  he  receives  one  piece,  on  he  goes 
to  make  friends  with  another  diner,  from  whom  he  obtains  another  piece  of 
meat  or  some  other  eatable,  and  only  later  on,  if  time  allows,  does  he  return 
to  the  diner  who  gave  him  the  first  piece.  In  behaviour  such  as  this  one 
must  recognise  an  immediate  judgment,  a  summary  form  of  reasoning  which 
resolves  itself  into  a  series  of  rigorously  logical  actions.  One  cannot,  however, 
conceive  of  reasoning  such  as  falls  within  the  category  of  successive  knowledge 
(trains  of  thought),  composed  of  syntheses  connected  one  with  another  and 
with  the  object  around  which  the  reasoning  process  revolves,  except  with  the 
aid  of  speech. 

Even  if  we  accept  the  evolutionist  doctrine  inaugurated  by  Darwin  and 
Spencer  it  is  needless  here  to  dwell  upon  the  various  types  of  logic — formal, 
dialectic,  genetic,  etc.  From  our  point  of  view  we  see  no  need  for  recognising 
differences  in  logical  objects,  as  classified  by  Baldwin — e.g.  hyperlogical 
objects  (aesthetic)  and  extralogical  objects  (moral).  Moral  objects  of  know- 
ledge are  strictly  logical  because  they  represent  a  series  of  experimental  facts, 
relating  both  to  the  individual  and  the  environment,  facts  that  are  closely 
linked  up  with  one  another,  whether  regarded  from  a  phylogenetic  or  from  an 
ontogenetic  point  of  view.  We  can  recognise  instances  of  departure  from 
this  law  when,  owing  to  habit  in  the  case  of  particular,  individual,  reflexes 
(conduct),  particular  actions  become  withdrawn  from  the  focal  point  of 
consciousness,  or  when,  as  sometimes  occurs,  a  great  effort  is  necessary  in 
order  to  overcome  egoistic  impulsions  in  face  of  social  obligations.  One  can 
understand  why  aesthetic  objects  are  considered  hyperlogical,  because  the 
sentiment  of  the  beautiful  is  not  subject  to  fixed  laws.  With  respect,  how- 
ever, to  the  moral  sentiment,  it  falls  within  experience  and  belongs  in  like 
degree  to  the  individual  and  to  an  entire  collection  of  people.  Logic,  as  an 
object  of  study,  reveals  the  laws  observed  by  thought  and  conduct  in  their 
evolution,  regarded  from  both  individual  and  collective  points  of  view. 
The  immutable  rules  of  logic  are  nothing  more  than  a  scientific  creation 
derived  from  the  facts  of  thought,  just  as  the  biologist  creates  a  type  of 
disease  by  deducing  it  from  observation  of  a  series  of  cases  of  the  same 
affection. 

Though  life  is  constantly  developing  and  expanding  so  that  the  elements 
of  thought  are  changing,  there  is  no  alteration  of  the  fundamental  laws 
regulating  the  formation  and  manifestation  of  thought,  these  laws  being 
those  of  perception,  memory  and  association,  on  which  logic,  as  a  science, 
is  reared.  Logic  draws  its  raison  d'etre  from  external  truths  and  physio- 
anatomical  truths. 

Logic  does  not  create  the  norms  and  conditions  of  exact  knowledge  in 


254  THE  MECHANISM  OF  THE  BRAIN 

the  sense  that,  without  an  acquaintance  with  these  norms,  exactness  and 
correctness  of  thought  would  not  be  possible.  It  may  be  said  of  logic  what 
Bacon  said  of  Moral  Philosophy.  One  may  be  a  professor  of  morals  and  yet 
not  follow  out  moral  precepts  in  life  ;  whilst  a  country  yokel,  who  possibly 
does  not  know  the  word  "  moral,"  may  throw  himself  into  an  angry  sea  to 
save  a  drowning  man.  It  does  not  create ;  rather  does  it  investigate  the 
laws  by  which  thought  is  formed  and  by  which  it  becomes  expressed  in  spoken 
or  written  languages  and  in  conduct.  The  actual  mode  of  thinking  is 
intimately  connected  with  the  mental  structure  of  each  individual  and  each 
social  group,  and  this,  in  turn,  draws  its  essence  and  its  form  from  the 
structure  of  the  brain,  and  from  the  physical  and  social  environment  in 
which  the  organ  of  thought  is  developed.  Logic  may  be  regarded  as  a 
technique,  the  object  of  which  is  to  perfect  the  structure  of  thought  in 
its  linguistic  form  (normative  discipline  of  Wundt)  ;  but  thought  always 
draws  its  component  elements  from  objective  perception,  either  directly  or 
indirectly,  and  also  from  the  relations  subsisting  between  these  elements. 
The  latter  become  combined  with  those  of  previous  experience  (memory)  and 
with  those  of  imagination  or  phantasy  which  in  turn  is  based  on  heredity 
and  upon  the  capacity  to  project  experiences  into  the  future. 

It  does  not  fall  within  the  scope  of  this  work  to  review  the  various  opinions 
regarding  the  scientific  conception  of  logic.  The  writer  is  unable  to  follow 
the  pure  intellectualists,  but  has  no  hesitation  in  accepting  the  notion  of 
the  evolutionists,  that  truth  does  not  come  from  reasoning,  however  correct 
that  may  be,  but  from  experience  in  the  widest  sense  of  the  term. 

Cerebral  disturbances  bring  into  evidence  logical  defects  that  are  clearly 
dependent  upon  a  mechanism  of  a  biological  character,  in  accordance  with 
a  law  which  can  no  longer  be  doubted.  All  errors  of  logic  in  thought  and 
conduct  are  due  either  to  defect  of  cerebral  evolution  or  to  a  process  of  dis- 
solution (disease)  of  the  organ  of  thought  and  conduct.  Mental  pathology 
furnishes  new  data  which,  taken  together,  afford  indisputable  proof  of  the 
fact  that  thought  is  the  result  of  a  biological  function,  and  logic,  which  reflects 
actual  modes  of  thinking,  is  a  biological  phenomenon  resulting  from  a  series 
of  more  elementary  phenomena  linked  up  with  one  another  and  having  an 
anatomical  basis.  These,  as  a  whole,  come  within  the  domain  of  psychology, 
which  cannot  be  considered  as  other  than  a  branch  of  physiology  and  biology. 
From  this  point  of  view,  logic  becomes  a  biophylactic  function.  When  the 
logical  process  loses  its  efficiency,  the  individual  or  social  group  loses  its 
most  certain  weapon  for  protection  in  its  struggle  for  existence  in  the  physical 
and  human  environment.  In  the  course  of  an  address  at  the  opening  of  the 
academic  session  in  the  University  of  Naples  1  and  in  a  series  of  lectures  upon 
fixed  ideas,2  the  writer  adopted  the  plan  of  applying  the  laws  of  biology  to 
mental  and  social  life,  a  conception  more  fully  developed  by  D'Ors,3  who, 

1  Bianchi.     "  Cervello  e  societa."      University  Annual.     Naples,  1891. 

2  Bianchi.     La  Clinica  Moderna.     An.  iv.     1899. 

3  D'Ors.      International    Congress    of    Psychology.     Reported    by    Ingenieros. 
Loc.  cit. 


APPENDIX  TO  CHAPTER  VIII  255 

in  a  study  of  logic,  arrived  at  the  conclusion  that  reason  is  a  diastasis  and 
logic  an  immunity. 

The  logical  process,  indeed,  is  founded  on  the  power  of  assimilation  and 
of  rejection  possessed  by  the  mental  products.  An  organism  lives,  evolves 
and  adapts  itself  according  to  the  extent  to  which  it  possesses  the-power  of 
assimilating,  dissimilating  and  eliminating  promptly,  in  accordance  with 
the  norms  regulating  each  species  of  living  organism.  To  assimilate  well 
signifies  to  incorporate  the  inorganic  and  organic  elements  that  are  useful 
or  indispensable  to  life,  and  to  eliminate  well  means  to  get  rid  of  elements 
produced  by  dissimilation,  and  harmful  to  life. 

If  these  conditions  were  not  strictly  observed,  life  would  not  be  possible  ; 
it  would  be  a  poor,  abnormal,  shortened  existence.  There  is  a  considerable 
group  of  bodily  diseases  in  which  this  fundamental  biological  function  is 
altered,  and  the  doctrine  here  referred  to  has  had  a  very  important  influence 
upon  the  development  and  advancement  of  human  pathology. 

We  meet  with  a  similar  state  of  affairs  in  mental  life.  A  well- organised 
mind  must  select  and  assimilate,  from  amongst  the  numerous  sensory 
products,  those  which  are  capable  of  serving  for  its  development,  becoming 
combined  with  other  psychic  elements  (assimilation)  and  constituting  more 
complex  mental  constellations — a  process  in  which  is  summed  up  the  con- 
ception of  evolution  and  progress  of  the  individual  as  a  unit  in  harmony  with 
the  environment.  This  capacity  is  an  essential  factor  of  the  logical  process. 
The  mind,  by  its  own  intrinsic  force,  eliminates  everything  which  does  not 
serve  the  ultimate  object  of  reasoning  and,  generally  speaking,  the  integrative, 
hedonistic  process  of  the  personality. 

Of  the  millions  of  stimuli  and  impressions  received  by  the  senses  and 
perceptive  centres  of  an  individual,  stimuli  which  reach  and  cross  the 
threshold  of  consciousness,  not  one  is  lost.  No  doubt,  only  a  relatively  small 
proportion  of  these  becomes  a  utilisable  capital,  which  can  be  re-evoked  accord- 
ing to  the  circumstances  of  the  varied  and  different  psychic  situations  which 
continually  succeed  one  another,  but  the  reason  is  that  the  remainder  becomes 
eliminated,  or  remains  hidden  in  the  depths  of  the  unconscious,  whence  it 
does  not  rise  again  to  the  surface  except  under  special  circumstances,  in 
certain  storms  and  abnormal  disturbances  of  mind.  In  the  case  of  minds 
badly  organised  (owing  to  morbid  heredity  or  other  degenerative  influences) , 
it  may  happen  that  the  psychic  metabolism  is  disturbed,  and  that  a  psychic 
component  which  ought  properly  to  fall  into  oblivion,  after  a  very  transitory 
passage  through  the  field  of  consciousness,  remains  in  consciousness  and  is 
not  eliminated,  reminding  us  of  the  poisons  that  are  sometimes  manufactured 
within  the  organism  from  substances  introduced  from  without  and,  not  being 
expelled,  accumulate  in  the  organism  which  has  produced  them.  These 
psychic  elements  that  are  not  eliminated  are  obsessions.  An  obsession  is  an 
illogical  thing.  That  this  is  so  is  demonstrated  by  the  fact  that  the  psychic 
personality  is  very  painfully  aware  of  its  presence  or  its  irrational  recurrence. 
The  personality  feels  afflicted  by  this  insistent  visitor,  recognises  its  helpless- 
ness in  front  of  it,  and  even  though  it  does  react  with  the  object  of  getting 


256  THE  MECHANISM  OF  THE  BRAIN 

rid  of  it,  it  often  happens  that  this  endeavour  only  results  in  increasing  the 
dominating  influence. 

Under  normal  conditions  an  idea  may  possess  developmental  potentiality 
and  exercise  a  beneficial  influence  in  polarising  and  directing  the  activity 
of  the  life  of  an  individual  towards  a  definite  end.  It  sometimes  assumes 
a  directive  power,  drawing  ever  more  and  moreupon  the  resources  of  the 
intellect,  becoming  more  expansive,  courting  the  mind,  illuminating  the 
intellectual  capital  of  a  people,  and,  when  transmitted  from  generation  to 
generation,  incarnating  the  principle  that  animates  a  period  of  history. 
Such  ideas  are  biophylactic,  they  are  like  the  regulating  centre  of  a  whole 
constellation,  of  a  sidereal  system ;  they  are  the  outcome  of  a  number  of 
social  and  historical  conditions,  and  at  the  same  time  the  shining  light 
which  guides  an  individual  or  a  country  in  the  progress  towards  a  happier 
existence.  They  have  a  wonderful  capacity  for  assimilation ;  they  draw 
freely  from  the  intellectual  capital,  and  in  turn  are  assimilated  with  the 
personality,  imparting  to  it  their  own  particular  warmth,  and  impressing  on 
it  the  movement  that  is  intrinsic  in  their  nature.  They  possess  an  extra- 
ordinary logical  and  determinative  power,  because  animated  by  sentiment. 
They  are  the  stars  which  guide  humanity  through  the  paths  of  progress. 
All  this  work  has  its  basis  in  logic. 

Weakness  of  the  mental  organism,  either  congenital  or  acquired,  forms 
the  substratum  of  the  obsessions,  and  serves  in  two  ways  to  produce  alogias 
and  dyslogias.  In  the  first  place  it  allows  only  a  scanty  number  of  ideas  or 
emotions  of  defence  to  be  opposed  to  illogical  emotions.  In  the  second  place, 
normal  ideas  are  less  active  in  these  subjects,  and  hence  are  incapable  of 
eliminating  abnormal,  useless  products  from  consciousness,  a  condition  of 
affairs  which  sums  up  the  conception  of  obsession.  In  individuals  with  weak 
inheritance  there  is  also  a  deficiency  in  the  power  of  detaining  the  object 
of  perception  in  the. focal  point  of  consciousness,  so  as  to  gather  the  greatest 
possible  number  of  features  that  go  to  build  up  a  more  complete  cognition. 
Not  only  so,  but  wider  and  fuller  knowledge  depends  also  on  the  capacity  to 
evoke  all  the  other  features,  similar,  analogous  or  contrasting,  from  which 
is  derived  the  perceptive  differentiation  of  what  the  external  world  presents 
to  us.  This  is  the  fundamental  reason  of  multiplication  of  fields  of  know- 
ledge, and  so,  too,  of  the  ramification  and  growth  of  the  sciences.  The  power 
of  detaining  an  object  of  perception  in  the  focal  point  of  consciousness  and 
of  evoking  its  specific  features  so  as  to  recognise  the  object  in  its  differential 
characters  constitutes  the  essence  of  the  psychic  fact  which  we  call  attention. 
This  is  defective  or  absent  in  idiots,  and  in  monkeys  that  have  suffered 
mutilation  of  the  frontal  lobes,  and  it  is  from  this  defect  that  the  alogias  and 
dyslogias  which  characterise  the  life  of  these  beings  arise. 

Pathology  thus  lends  additional  confirmation  of  the  views  already  ex- 
pressed. Alogias  and  dyslogias  result  from  definite  processes,  the  mechanism 
of  which  is  quite  well  known.  From  the  dynamic  and  functional  point  of 
view,  they  also  depend  upon  defects  of  perception,  memory,  imagination  and 
association,  and  upon  the  intervention  of  extraneous  elements  in  the  reasoning 


APPENDIX  TO  CHAPTER  VIII  •  257 

process — emotions,  delusions,  hallucinations.  Man  is  all  the  more  logical 
in  the  sense  already  explained,  or,  in  other  words,  he  is  the  better  provided 
with  biophylactic  power  the  more  his  perceptive  force  is  able  to  penetrate 
things  and  situations  and  so  arrive  at  precise  knowledge.  The  work  of 
perception  is  fundamental  as  regards  both  knowledge  and  logic.  When 
perception  is  partial  or  superficial  the  conclusions  are  insufficient,  and 
represent  a  deviation  from  that  form  of  reasoning,  or  that  logic  in 
conduct  and  in  speech,  which  bears  the  stamp  of  reality.  Such  con- 
clusions are  of  no  real  value  for  the  purposes  of  progress.  All  imbeciles 
and,  to  a  greater  extent,  idiots  fall  into  a  number  of  errors,  and  are 
inconclusive  and  inefficient  because  they  lack  the  means  of  penetrating 
reality,  of  apperceiving  it,  and  of  initiating  action  that  is  adequate  in  the 
biophylactic  sense. 

The  perceptive  process  is  thus  closely  bound  up  with  attention.  Defect 
of  the  one  involves  defect  of  the  other.  The  psychic  arcs  in  these  cases  are 
short,  and  terminate  in  inadequate  actions  or  in  phrases  which,  if  not  illogical, 
considered  per  se,  are  at  least  illogical  as  regards  their  insufficiency  and  their 
unsuitability  for  the  needs  of  life.  In  all  cases  of  this  kind  we  have  to  deal 
either  with  pathological  processes,  general  or  partial,  occurring  in  the  period 
of  development  (infancy),  and  arresting  the  process  of  maturation  of  the 
brain,  or  else  with  a  biological  insufficiency  of  the  organ  of  thought,  which, 
from  the  outset,  is  incapable  of  reaching  the  normal  degree  of  development. 
Almost  the  entire  brain  is  affected  by  the  evolutionary  defect,  no  matter 
what  its  cause,  but  most  of  all  the  frontal  lobe,  and  especially  the  layer  of 
small  and  large  (external  and  internal)  pyramidal  cells  (vide  Chapter  III.). 
Degenerative  processes  in  the  cells  of  the  cerebral  cortex,  particularly  in 
the  frontal  lobe,  produce  similar  effects  in  adults,  having  due  regard  to 
the  mental  structure  of  each  individual. 

Every  degenerated  or  degenerating  cell  represents  a  loss  of  energy  to  the 
cerebral  dynamics.  Just  as  an  electric  battery  gives  a  lower  voltage  when 
the  salts  in  the  cells  have  been  consumed  and  the  relation  between  electro- 
motor force  and  resistance  altered,  in  the  same  way  the  intellectual  power 
is  curtailed  and  the  relative  logical  disposition  of  thought  disturbed  when 
degeneration  occurs  in  a  certain  number  of  nervous  elements  [of  possible 
causes  there  are  many — intoxications,  autointoxications,  overwork  (leading 
to  autointoxications),  alterations  of  the  vascular  walls,  insufficiency  of  the 
internal  secretions,  etc.]. 

The  same  factors  produce  defects  of  memory  and  of  the  associations, 
especially  when  there  is  degeneration  or  interruption,  from  one  cause  or 
another,  of  the  associative  paths.  Apart  from  this,  however,  there  exists 
a  group  of  alogias  or  hypologias  which  depend  upon  a  feeble  capacity  to 
detain  a  theme  in  the  focal  point  of  consciousness  and  to  evoke  and  select 
the  elements  required  in  the  process  of  reasoning.  This  evocative  and 
selective  power  serves  as  a  regulator  of  the  function  of  the  sensory  cortex, 
and  when  it  is  weak  the  sensory  areas  fail  to  furnish  the  components  which 
are  necessary  for  the  construction  and  logical  course  of  thought,  or  give  their 
R 


258*  THE  MECHANISM  OF  THE  BRAIN 

products  only  under  the  compelling  influence  of  strong  internal  and  external 
excitement.  In  another  group  of  cases  the  sensory  products  arise  without 
any  rule  or  order,  and  so  we  get  a  state  of  mental  confusion.  The  detentive 
capacity  in  question  is  always  found  to  be  weakened  in  any  degenerative  or 
sub -evolutionary  process  affecting  the  frontal  lobe. 

The  extraneous  elements  which  intervene  in  the  reasoning  process  are 
delusions,  hallucinations  and  strong  emotions.  Primary  delusions — those, 
that  is  to  say,  which  are  not  the  direct  product  of  hallucinations — are  con- 
ceptions which  arise  and  thrive  upon  an  abnormal  emotional  basis  (fear, 
religion,  vanity,  pride)  ;  they  have  no  counterpart  in  reality  yet  are  upheld 
with  arguments,  and  sometimes  with  strong  dialectic  power,  in  an  apparently 
logical  and  connected  fashion.  The  false  conception,  like  a  presupposition 
the  reality  of  which  is  a  matter  apart,  makes  the  cerebral  powers  subservient 
to  it ;  all  the  apparently  logical  and  pertinent  arguments  that  the  deluded 
individual,  according  to  his  mentality  and  culture,  brings  forward  to  support 
his  thesis  are  furnished  by  unconscious  cerebration,  and  not  only  do  these 
lack  entirely  any  basis  in  fact  but  often  the  very  premises  with  which  he  sets 
out  are  obviously  improbable. 

In  this  case  the  attentive  capacity  is  subjugated  by  a  higher  power 
(passional  preconception),  which  pervades  all  the  mental  mechanisms  and 
withstands  any  counter  argument  that  the  perceptive  process  might  furnish 
in  opposition,  the  perceptive  process  itself  being  enslaved  by  the  delusion, 
which  triumphs  in  a  world  of  fancies. 

The  alogias  that  arise  from  hallucinations  are  the  effect  of  an  abnormal 
condition  (inflammation,  intoxication,  congestion)  of  those  same  areas  which 
we  considered  to  be  the  organs  for  the  construction  of  the  images.  The 
creative  power  of  the  brain  is  manifest  not  only  in  thought,  in  its  wide  and 
complete  structure,  but  also  in  single  images.  These  appear  to  consciousness 
as  realities  projected  into  the  world  without.  There  may  be  a  single  image 
or  there  may  be  a  few  or  many,  but  in  point  of  fact  they  neither  reflect  nor 
represent  reality.  They  constitute  a  world  of  dreams  with  some  features  of 
reality,  and  are  confounded  with  objective  reality  which  the  patient  is  still 
able  to  perceive  in  part.  Confusion  results  from  this,  inasmuch  as  the 
hallucinated  individual  perceives  real  things  along  with  the  images  of  his 
dream,  this  state  of  affairs  being  aggravated  by  the  fact  that  he  has  only  an 
imperfect  perception  of  the  real  things,  whilst  the  phantasms  take  the  place 
of  reality  in  his  consciousness,  dysorientating  it,  decomposing  it,  and  inciting 
to  immediate  reactions  in  speech  and  conduct,  for  hallucinations  are  furnished 
with  a  strong  determinative  power. 

One  can  readily  understand  that  the  pathological  process  which  determines 
the  hallucinations  will  at  the  same  time  cause  a  marked  disturbance  of  the 
perceptive  process,  because  it  is  one  and  the  same  organ  that  is  involved, 
and  that  it  will  interrupt  the  relations  of  the  self  with  the  preperceived  real 
world  ;  for  hallucinations,  like  dreams,  transport  the  disturbed  consciousness 
into  a  fantastic  world  which  obeys  none  of  the  laws  regulating  the  relations 


APPENDIX  TO  CHAPTER  VIII  259 

of  consciousness  with    reality,   and,   in  consequence,   speech  becomes  in- 
conclusive and  conduct  illogical. 

There  is  a  marked  difference  between  these  various  alogias,  hypologias, 
dyslogias  and  the  conditions  already  mentioned  as  arising  from  lesions  of 
the  language-zone  on  the  one  hand,  and  alogia  due  to  experimental  ablations 
in  monkeys  or  to  severe  bilateral  lesions  of  the  frontal  lobes  in  man,  on  the 
other.  In  the  latter,  the  evocative  capacity  is  defective  and,  consequently, 
the  activity  designated  as  phantasy  or  imagination  is  suppressed  or  much 
reduced,  even  in  its  simplest  form,  such  as  that  excited  by  desire  and  the 
appetites.  Perceptive  recognition  of  objects  takes  place,  but,  as  in  the  case 
of  the  imbecile,  perception  is  not  rendered  more  perfect  and  complete  by 
elements  of  apperception,  because  the  evocation  is  simple.  Comparisons  are 
not  arrived  at,  because  association  is  defective,  so  that  a  monkey,  per- 
ceiving the  white  colour  and  the  form  of  a  piece  of  chalk,  mistakes  it  for 
sugar  ;  he  takes  it  and  puts  it  in  his  mouth  and,  even  after  he  perceives  the 
taste  of  the  chalk,  which  is  not  sweet,  does  not  resolve  to  spit  it  out.  That 
is  a  variety  of  dyslogia.  The  relations  are  simple,  disjointed,  varied,  isolated, 
and  so,  in  man,  the  discourse  is  poor  and  the  conduct  illogical.  Past  experi- 
ence is  not  utilised — e.g.  a  monkey,  tricked  many  times  in  succession,  does 
not  appreciate  the  fact,  but  stupidly  repeats  the  same. illogical  actions  which 
bring  him  no  success.  The  resemblance  between  this  and  the  mental  state 
of  imbeciles  is  very  remarkable. 

Profound  imbeciles  not  only  fail  to  arrive  at  the  formation  of  general 
and  categorical  ideas,  but  are  especially  incapable  of  detaining  a  particular 
theme  in  the  focal  point  of  consciousness.  The  logical  power  that  is  a  feature 
of  normally  developed  men  is,  consequently,  entirely  beyond  their  attain- 
ment, and  if  the  phrases  which  they  sometimes  pronounce  seem  to  have 
something  of  a  logical  character  about  them,  they  nevertheless  represent 
immediate  reflex  arcs  and  responses  to  single  stimuli.  Their  conduct  is 
disjointed  and  exhibits  no  succession  of  facts  connected  one  with  another. 

Thus,  then,  psycho -pathology  comes  to  our  aid,  helping  us  to  complete 
and  consolidate  our  conception  of  logic,  regarded  from  the  point  of  view  of 
the  function  of  the  cerebral  mantle.  The  various  alogias  and  dyslogias  that 
result  from  different  pathological  conditions  furnish  a  positive  proof  of  the 
physio -anatomical  basis  of  logic  and  of  the  mechanism  underlying  the 
development  and  expression  of  human  thought  and  conduct. 


CHAPTER  IX 

Emotions  and  Sentiments 

Two  orders  of  facts  have  their  beginnings  in,  and  develop  from,  sensation. 
One  represents  the  intellect  and  its  various  grades  of  evolution;  the  other 
the  degrees  and  forms  of  feeling  and  of  emotion.  The  one  has  reference  to 
the  external  world  and  its  relations,  translated  into  images  with  their  respec- 
tive associations ;  the  other  to  modifications  of  the  ego,  provoked  not  only 
by  stimuli  from  without  but  also  by  chemical  and  vital  processes  taking  place 
within  the  organism,  under  the  influence  of  these  stimuli  and  of  all  the  mental 
products,  simple  and  complex,  derived  from  them,  in  intimate  relation  with 
the  cognitions  of  the  external  world.  The  one  proceeds  unceasingly  in  its 
development,  and,  with  the  constant  aid  of  grafts  from  the  external  world, 
reaches  the  summit  of  knowledge,  a  summit  which  is  ever  becoming  higher ; 
the  other  evolves  from  the  elementary  emotions  of  pleasure  and  pain,  originat- 
ing in  the  chemical  changes  that  succeed  one  another,  and  broadens  out  to 
embrace,  in  synthetic  fashion,  the  emotions  and  sentiments  of  other  fellow- 
beings  scattered  over  the  face  of  the  earth.  The  intellect  finds  its  objective 
in  cognition  of  the  universe  ;  the  sentiments,  through  the  experiences  of  the 
ego  in  its  changing  climatic  and  social  relations,  promote  understanding  of 
consciousness  between  human  beings,  in  the  general  aspiration  after  a  happier 
life,  and  the  struggle  against  pain. 

Emotion  is  inherent  in  the  modifications  of  the  organic  being  that  take 
place  under  the  action  of  stimuli.  In  the  first  representatives  of  animal  life, 
this  modification  is  of  a  chemical,  physical  or  mechanical  nature.  The  facts 
of  tropism,  already  alluded  to,  contain  a  rudimentary  emotional  element. 
This  gradually  becomes  more  conspicuous  as  it  becomes  complicated  with 
the  psychic  phenomena  that  appear  in  the  successive  stages  of  development 
of  the  nervous  system.  The  behaviour  of  the  amoeba,  when  brought  into 
proximity  with  an  acineta,  is  a  characteristic  example  of  tropism.  Electricity, 
light,  heat,  cold,  are  powerful  modifiers  of  the  organic  processes  and  act 
either  directly,  or  by  means  of  chemical  products,  on  the  nervous  system, 
from  the  moment  that  this  makes  its  appearance ;  and  they  bring  about 
conditions  that  form  the  basis  of  emotion. 

Pressure  and  electric  changes  in  the  atmosphere  are  felt  by  many  animals, 
which  seek  shelter  from  an  approaching  storm  before  it  can  be  perceived  by 
means  of  the  ordinary  organs  of  sense.1 

That  physical  agents  exert  a  remarkable  influence  upon  the  process  of 
nutrition,  and  these  again  upon  the  psychic  functions,  are  facts  that  have 
been  known  from  antiquity.     The  influence  of  climate  and  the  seasons  upon 
1  Hunter,  Y.     (Euvres  completes.  1841. 

260 


EMOTIONS  AND  SENTIMENTS  261 

the  organic  and  psychic  functions  has  been  demonstrated  by  statistics 
relating  to  suicide,  which  is  more  frequent  in  certain  seasons  (Montesquieu, 
Bourbousson,  Delaroche,  Morselli,  Massarotti).  There  are  both  old  and 
recent  observations  connected  with  this  subject,  and  amongst  the  latter  may 
be  mentioned  the  researches  of  Lombroso,1  Enrico  Ferri,2  and  Penta,3  in 
Italy,  dealing  with  the  influence  of  the  seasons  upon  insanity  and  upon  the 
frequency  of  crime. 

Climate  is  the  synthesis  of  a  number  of  physical  conditions — light,  tem- 
perature, atmospheric  electricity,  direction  and  prevalence  of  certain  winds, 
vicinity  to  the  sea  (independently  of  atmospheric  pressure)  and  the  chemico- 
physical  constitution  of  the  earth.  We  know  that  in  the  human  subject, 
metabolism  undergoes  notable  alterations  in  different  climates,  and  with 
these  we  get  certain  changes  in  the  humour  and  activity  of  the  mind  in 
individuals  not  adapted  to  the  particular  climate. 

This  has  been  confirmed  particularly  in  the  case  of  persons  of  exquisitely 
nervous  temperament.  In  some  climates  neuropaths  do  not  sleep,  they  are 
more  irritable  and  more  restless,  whilst  epileptics  under  identical  conditions 
of  life,  so  far  as  food  and  muscular  exercise  are  concerned,  and  pursuing  the 
same  treatment  as  had  obtained  elsewhere,  are  subject  to  a  much  greater 
number  of  fits.  It  is  strikingly  suggestive  that  this  phenomenon,  if  not 
of  the  same  nature  as,  is  at  least  fundamentally  analogous  to,  that  of 
tropism.  When,  again,  we  think  of  the  great  influence  exercised  upon  the 
nervous  system  by  factors  connected  with  digestion  and  nutrition,  it  seems 
evident  that  the  emotions  are  closely  bound  up  with  the  organic  processes 
taking  place  within  the  organism. 

The  fact,  affirmed  by  Claude  Bernard  and  definitely  confirmed  by  Canalis 
and  Morpurgo,  that  badly  nourished  animals  are  much  more  prone  than  others 
to  infections,  is  a  proof,  from  another  source,  of  the  intimate  relations  subsisting 
between  all  vital  phenomena,  emotions  included,  when  the  organisms  are  sub- 
jected to  the  action  of  external  agents,  in  the  changing  conditions  of  existence. 

The  silence  which  night-time  imposes  upon  many  animals ;  the  slowing 
of  conversation,  the  difficulty  or  inhibition  which  we  experience,  as  though 
taken  by  a  vague  fear  or  preoccupation,  if  the  light  goes  out  as  we  are  talking  ; 
and  the  gaiety  which  bright  sunshine  infuses  into  us  after  days  of  wet  and 
wintry  weather,  are  psychic  equivalents,  in  the  domain  of  the  emotions, 
intimately  connected  with  all  the  vital  functions  and  hence  with  the  organic 
processes.  Moleschott,  Fubini  and  Benedicenti  have  shown  that  the  quantity 
of  carbonic  acid  given  off  in  darkness  and  in  sunlight  respectively  is  in  the 
ratio  of  3  to  5.4  The  amplitude  of  the  respiratory  movements  under  the 
influence  of  white  light  is  different  from  that  under  coloured  rays. 

1  Lombroso.    L'uomo  delinquente,  1884  ;  C.  Lombroso  and  G.  Ferrero.   La  donna 
delinquente.     1915. 

2  E.  Ferri.     Atlante  antropologico  delVomicldio.   1895. 
'Penta.     /  pervertimenti  sessuali  nelVuomo.   1893. 

4  Moleschott,  Fubini  and  Benedicenti.  "  Influence  de  la  lumiere  sur  le  chimisme 
de  la  respiration."  Arch.  Ital.  di  Bid.  1891. 


262  THE  MECHANISM  OF  THE  BRAIN 

Every  neuropathologist  who  has  had  practical  experience  in  the  treat- 
ment or  investigation  of  hysterical,  neurasthenic  or  neuropathic  patients 
is  well  aware  of  the  fact  that  the  humour  of  mind  and  behaviour  of  these 
patients,  in  the  family  and  social  relations,  alter  with  atmospheric  changes. 
The  modifications  undergone  by  the  circulation  under  the  influence  of  various 
external  stimuli  acting  upon  the  different  senses,  modifications  that  have 
been  clearly  demonstrated  since  the  introduction  of  Mosso's  plethysmograph 
•as  an  aid  to  physiological  investigations,  are  now  assured  facts  of  physiology 
and  psychology. 

Clinical  psychiatrists  are  familiar  with  the  fact  that  some  melancholies 
and  neurasthenics  suffer  nocturnal  anguish,  in  which  the  modifications  of 
the  circulation  and  respiration  induced  by  darkness  play  a  part ;  and  that 
hallucinations  with  delusional  representations  and  anxious  states,  which 
sometimes  resolve  themselves  into  suicidal  impulses,  are  more  frequent  in  the 
night-time  and  towards  the  morning  hours. 

These  phenomena  are  but  the  reflex  of  chemical  alterations,  taking  place 
within  the  organism,  upon  the  humour  of  the  mind  and  the  psychic  pro- 
cesses, in  the  sphere  of  the  emotions,  just  like  the  tropisms  of  lower  organisms 
but  on  a  much  higher  scale,  and  embracing  an  order  of  facts  of  much  greater 
complexity. 

This  complexity  is  caused  by  the  intervention  of  the  nervous  system 
with  its  intricate  structure,  which  is  readily  affected  by  all  the  chemico- 
physical  endorganic  modifications ;  many  of  these,  when  abnormal,  are 
revealed  to  consciousness  in  the  form  of  malaise  accompanied  by  change  of 
humour  and  greater  excitability,  along  with  a  sense  of  ennui,  fastidium 
and  sometimes  gloomy  notions. 

On  other  occasions  these  modifications  reveal  themselves  by  unusual 
irritability  and  intolerance  in  the  family  and  social  relations,  or  by  a  sense  of 
depression,  or  by  unfounded  gaiety. 

The  humour  of  mind,  be  it  gay  or  sad,  and  the  psychic  activity  are  closely 
connected,  each  in  the  same  way,  with  the  chemical  and  physical  changes 
going  on  in  the  organism.  It  often  happens  that  we  are  more  or  less  disposed 
to  act  or  not  to  act,  to  be  generous  or  harsh,  confident  or  diffident,  optimistic 
or  pessimistic,  owing  to  modification  of  the  kinaesthetic  sense,  and  this  in 
turn  is  influenced  by  the  chemical  and  physical  alterations  which  follow  one 
another  in  the  organism.  Hunger,  thirst,  the  sexual  appetite,  tasty  sub- 
stances, aromatic  drinks,  perfumes,  contacts,  all  provoke  emotion,  either  of 
pleasure  or  of  disgust,  hence  a  desire  and  attempt  to  approach  or  to  retreat. 
A  good  dinner  followed  by  healthy  digestion  makes  a  man  generous  ;  hunger 
and  bad  digestion  render  him  pessimistic  and  intractable.  The  fundamental 
emotions  can  thus  be  traced  back  to  their  genesis — i.e.  to  the  chemical 
alterations  taking  place  within  the  organism,  alterations  which  reverberate 
upon  the  kinsesthetic  sense,  which  is  the  psychic  foundation  of  emotion. 

The  two  fundamental  emotions,  pleasure  and  pain,  are,  in  man,  intimately 
bound  up  with  somatic  phenomena.  In  proportion  as  the  organs  become 


EMOTIONS  AND  SENTIMENTS  263 

more  perfect  and  acquire  more  intimate  relations  with  one  another,  or,  in 
other  words,  as  the  organic  machine  becomes  more  complicated,  the  emotions 
become  accompanied,  as  we  shall  see,  by  particular  organic  phenomena 
which,  at  bottom,  are  the  most  authentic  expression  of  chemical  modifica- 
tions of  the  protoplasm  under  the  action  of  external  agents,  such  as  we 
found  to  underlie  the  phenomena  of  tropism.  In  this  notion  is  summed  up 
the  modern  doctrine  of  energetics. 

The  continuous  chemico-dynamic  processes,  the  perennial  action  of  the 
stimuli  of  the  external  world,  generate  in  man,  who  is  the  most  complex 
and  perfect  morphological  machine,  the  sense  of  life  and  of  self -existence, 
in  association  with  the  sense  of  reactive  energy,  or,  in  other  words,  the  kin- 
assthesis.  This  is  but  the  reflex,  on  the  threshold  of  consciousness,  of  all 
the  inner  work  of  the  busy  organic  laboratories  and  of  the  incessant  stimuli 
by  which  the  outer  world,  in  which  we  live,  reveals  itself  to  us.  In  1889 
the  author  wrote : 

"  The  kinsesthetic  sense  is  the  synthesis  of  all  the  sensations  in  which 
the  organic  personality,  the  psycho-physical  ego,  is  summed  up.  To  it 
contribute  not  only  the  special  senses  by  means  of  which  we  experience  an 
infinite  series  of  immediate  relations  with  the  external  world,  the  ultimate 
resultant  of  which  is  the  progressive  comprehension  of  our  own  organism  as 
distinct  from  the  environment  in  which  we  live,  but  also  the  mnemonic 
reproduction  of  the  physical  or  organic  qualities  of  the  organism,  provided 
by  all  those  other  currents  which  establish  uninterrupted  relations  between 
the  organs  innervated  and  the  higher  nerve-centres.  The  latter  currents  do 
not  excite  true  states  of  consciousness,  and  therefore  do  not  give  rise  to  sensa- 
tions in  the  strictly  psychological  sense  of  the  word,  but,  along  with  the  impres- 
sions from  without,  they  are  confluent  in  a  chamber  of  harmonic  resonance, 
the  waves  of  which  give  rise  to  the  sense  of  our  own  proper  existence. 

"It  is  this  sense,  which  is  known  as  the  kincesthetic  sense,  that  is  the 
fundamental  constituent  element  of  consciousness,  although  it  is  one  of  the 
least  representative. 

"  Any  discordant  note,  generated  in  any  of  the  organs  and  disturbing  the 
harmony  of  the  waves,  is  a  cause  of  conflict  in  the  chamber  of  resonance,  and 
we  become  aware  of  it  in  the  form  of  malaise."  1 

It  is  the  chief  instrument  of  the  emotions  ;  it  represents  the  soil  in  which 
they  germinate ;  it  furnishes  the  somatic  elements  of  emotion,  and  prepares 
the  way  for  the  representations,  which  are  the  other  constituent  elements  of 
emotion. 

From  all  parts  of  the  organism  which  are  organic  laboratories  there  is  a 
continuous  flow  of  nerve-waves,  establishing  relations  between  the  organs 
and  the  higher  nerve-centres.  With  these  are  conjoined  all  the  special 
sensations  through  which  we  experience  a  series  of  mutations  due  to  im- 
mediate contacts  with  the  external  world,  the  ultimate  result  being  the 
progressive  comprehension  of  our  own  organism,  which  becomes  ever  more 
distinct  from  the  environment. 

1  Bianchi.     Semiotica  delle  malattie  del  sistema  nervoso.     Milan,  1889. 


264  THE  MECHANISM  OF  THE  BRAIN 

We  have  said  that  the  kinsesthetic  sense,  though  not  a  distinctly  con- 
scious element — i.e.  distinctly  represented  in  the  waking  consciousness  as 
such — yet  becomes  an  element  of  waking  consciousness  in  all  the  more  out- 
standing vicissitudes  of  the  ego,  in  its  external  and  internal  environment ; 
it  becomes  more  prominent  whenever  there  is  functional  difficulty,  or  a  state 
of  conflict,  as  the  result  either  of  excessive  intensity  of  the  external  stimuli, 
these  being  so  powerful  as  to  be  actually  disintegrating  (pain),  or  of  in- 
sufficient intensity  of  these  (anaesthesia,  hypoeesthesia,  paralysis),  or  because 
of  an  intensified  general  tone,  or  a  dissonant  note  arising  from  one  or  other 
organ  and  disturbing  the  harmony  in  the  chamber  of  organic  resonance, 
where  organic  consciousness  takes  its  form.  In  this  case  we  get  a  sense  of 
ill-being  and  a  lowering  of  tone,  and  the  result  is  a  new  attitude  of  conscious- 
ness. The  kinsesthetic  sense  thus  becomes  at  the  same  time  a  regulator  of 
the  emotional  susceptibilities  of  the  ego. 

An  intimate  connection  exists  between  the  kinsesthesis  and  the  sphere  of 
the  images,  so  that  variations  in  the  tone  of  the  kinsesthesis  tend  to  recall 
into  the  focal  point  of  consciousness,  through  the  law  of  association,  deter- 
mined categories  of  ideas,  aspirations  and  tendencies.  Thus  are  explained 
the  particular  inclinations,  trends  and  emotional  susceptibilities  that  are 
peculiar  to  separate  individuals.  Elements  for  the  kinsesthesis  are  furnished 
by  the  larger  part  of  the  cerebral  mantle,  for  even  the  specialised  sensory 
areas  have  their  motor  centres  and  possibly  also  some  tactile  representation. 

The  cerebral  cortex  besides  being  the  organ  that  gives  rise  to  images, 
movements  and  the  higher  psychic  functions,  is,  at  the  same  time,  an 
anatomical  field,  experimental  excitation  of  which  gives  rise  to  modifications 
of  the  organic  functions.  The  respiration,  the  circulation,  the  secretions 
and  the  movements  of  the  internal  organs  are  represented  on  the  cortex  of 
the  brain.  There  is  ample  experimental  proof  of  the  fact  that  the  cerebral 
mantle  has  acquired  relations  with  all  the  viscera — i.e.  with  each  unit  of 
the  vital  workshop — and  transforms  their  work  into  a  psychic  synthesis 
which,  along  with  all  the  intellectual  and  emotional  products,  goes  to  form 
consciousness. 

The  literature  dealing  with  these  experiments  is  a  very  rich  one,  and  only 
the  most  outstanding  and  assured  facts  can  here  be  referred  to. 

Respiration  is  accomplished  and  modified  in  a  mechanism  that  is  ex- 
traneous to  the  focal  field  of  consciousness,  but  it  is  also  capable  of  modifica- 
tion by  the  will  and  by  stimuli  which  cross  the  threshold  of  consciousness,  as 
well  as  by  representations  furnished  by  memory.  In  support  of  the  latter 
contention  the  fact  may  be  mentioned  that,  leaving  aside  the  examination  of 
the  lower,  unconscious,  respiratory  arc,  a  cortical  field  has  been  discovered, 
experimental  excitation  of  which  gives  rise  to  marked  alterations  of  respiration. 

Without  dwelling  upon  the  researches  of  Lepine,  Bochefontaine,  Munk 
and  Danilewski,  it  may  be  said  that  recent  investigations,  especially  those 
Carried  out  in  the  physiological  laboratory  of  Bechterew,1  prove  that  modi- 
1  Bechterew.  "  t)ber  der  Epilepsia."  Sammlung  Klinischer  Vortrdge.  1897. 


EMOTIONS  AND  SENTIMENTS  265 

fications  of  respiration  occur  on  exciting  a  very  circumscribed  area  on  the 
third  primary  convolution  in  the  dog,  in  close  proximity  to  the  excitable 
area  for  the  orbicularis  palpebrarum.  Electric  stimulation  at  this  point 
produces  slowing  and  even  arrest  of  respiration.  Probrazenski  obtained 
similar  results  in  dogs.1 

Horsley  and  Semon2  obtained  modifications  of  respiration  on  exciting 
the  cortical  centre  of  the  larynx  (respiration  is  closely  associated  with  the 
voice  and  with  crying).  They  obtained  acceleration  and  reinforcement  of 
respiration  on  exciting  a  point  in  the  vicinity  of  the  lower  extremity  of  the 
crucial  sulcus. 

Giannelli,3  in  the  course  of  his  investigations,  found  two  points  where 
excitation  gave  rise  to  altered  respiration  ;  one  on  the  sigmoid  gyrus  above 
and  in  front  of  the  crucial  sulcus,  near  the  interhemispheric  fissure,  con- 
cerned with  expiratory  movements,  and  a  second  situated  further  forwards, 
at  the  upper  extremity  of  the  presylvian  fissure. 

Langelaan  and  Beyermann4  found  a  similar  centre  on  the  sigmoid  gyrus. 
On  exciting  a  small  area  near  the  crucial  sulcus  they  obtained  acceleration 
and  greater  depth  of  respiration,  with  a  tendency  towards  inspiratory  arrest 
of  the  thorax.  Extirpation  of  this  centre  was  followed  by  slowing  and 
irregularity  of  the  respiratory  movements  and  by  sighing. 

Bechterew,  in  his  later  researches,  seems  to  have  defined  with  greater 
precision  the  points  on  the  cerebral  cortex  of  the  dog  where  excitation  causes 
modification  of  respiration.  According  to  him,  one  point  would  be  situated 
at  the  inferior  extremity  of  the  crucial  sulcus,  on  the  anterior  branch  of  the 
sigmoid  gyrus,  and  would  have  to  do  with  the  acceleration  of  respiration. 
A  second  point  would  be  found  at  the  anterior  extremity  of  the  sulcus  which 
divides  the  second  from  the  third  external  convolution,  near  the  posterior 
branch  of  the  sigmoid  gyrus,  and  would  be  concerned  with  slowing  of  respira- 
tion, proceeding  to  arrest  in  expiration.  A  third  point  would  be  located  at 
the  upper  extremity  of  the  presylvian  fissure,  and  would  be  concerned  with 
deepened  respiration  and  slowing  of  the  movements,  proceeding  to  arrest 
in  inspiration.5 

The  objection  has  been  raised  that  there  are  various  points  on  the  cerebral 
cortex  where,  according  to  the  results  of  the  experiments  of  different  in- 
vestigators, electric  excitation  produces  alterations  of  respiration. 

This  diversity  in  localisation  is  due,  at  least  in  part,  to  the  complicated 
mechanism  of  respiration,  and  to  the  relations  of  respiration  with  all  the 
cortical  functions.  The  assertion  of  Bochefontaine  and  Fra^ois  Frank  that 
excitation  of  any  point  whatsoever  of  the  cortex  gives  rise  to  modification 

1  Probrazenski.     "  tlber    das     Atmungs centrum    in    der    Hirnrinde."     Wiener 
Klinische  Wochenschrift.     1890. 

2  Horsley  and  Semon.     "  An  Experimental  Investigation  of  the  Centre  of  Motor 
Innervation  of  the  Larynx."     Proc.  Roy.  Soc.  of  London.     1890. 

3  Giannelli.     "  L'influenza  della  corteccia  cerebrale,"  etc.     Ann.  di  Net;.     1900. 

4  Beyermann.     "  On   the  Localisation  of  a  Respiratory  Centre,"  etc.     Brain. 
1903. 

5  Bechterew.     Die  Functionen  der  Nervencentra.     1911. 


266  THE  MECHANISM  OF  THE  BRAIN 

of  respiration  does  not,  however,  seem  probable,  and  is  on  the  same  level 
as  the  other  statement  that  epilepsy  can  be  provoked  by  exciting  any  area 
of  the  cerebral  cortex.  These  cases  of  modifications  of  respiration  and 
circulation,  induced  by  electric  excitation  of  cortical  areas  far  removed  from 
the  sigmoid  gyrus  (or,  in  the  monkey,  from  the  Rolandic  convolutions),  find 
their  explanation  in  the  excessive  intensity  of  the  current  employed  in  the 
experiments.  In  any  case,  the  question  remains  sub  judice.  Even  putting 
aside  the  complicating  effects  of  all  strong  electric  currents,  it  may  be  held 
that  any  excitation,  even  moderate,  of  the  sensory  areas  reawakens  images 
(hallucinatory)  which  give  rise  to  modifications  of  respiration,  varying  accord- 
ing to  the  animals  experimented  upon  and  their  emotional  susceptibilities. 

There  is  no  question  as  to  the  relations  subsisting  between  the  musculature 
concerned  with  the  respiratory  movements  and  those  of  mimicry,  phonation, 
deglutition  and  the  movements  of  the  trunk.  These  motor  centres  are  sub- 
ordinate on  one  hand  to  the  will,  and  on  the  other,  quite  apart  from  will,  to 
the  state  of  the  sensory  areas  whence  arise  the  associative  reflexes  (Pavlov, 
Bechterew)  and  the  affective  attitudes,  which  are  almost  always  accompanied 
by  modifications  of  the  respiratory  rhythm,  of  the  circulation,  the  secretions, 
etc. 

As  a  matter  of  fact,  electric  excitation  of  certain  points  of  the  motor  area 
gives  rise  to  marked  modifications  of  the  function  of  the  heart,  of  the  pulse 
and  of  the  blood  pressure.  It  seems  evident  that  the  cortex  has  an  influence 
not  only  upon  respiration  but  also  upon  the  activity  of  the  heart.  Inves- 
tigations carried  out  for  some  time  by  Tomasini,  in  the  writer's  clinique, 
confirmed  these  results  in  the  main. 

Researches  both  old  and  recent,  amongst  which  may  be  mentioned  those 
of  Schiff,  Danilewski,  Bochefontaine,  Eckard,  Frank,  Bechterew,  Mislawski, 
and  especially  those  of  Cerevkov,1  have  furnished  ample  evidence  to  support 
the  contention  that  the  cerebral  cortex  and  the  corresponding  white  substance 
exercise  a  decisive  influence  upon  the  function  of  the  heart  and  vessels ; 
the  region  indicated  is  the  sigmoid  gyrus  (in  dogs),  the  pre- crucial  perhaps 
more  than  the  post-crucial  portion. 

These  facts  have  a  very  important  bearing  upon  psychology.  In  the 
emotions  we  have  modified  not  only  respiration  but  also  the  circulation. 
Emotion-producing  impressions  from  without  and  their  representations  or 
memories,  the  former  much  more  than  the  latter,  are  accompanied  by  dis- 
turbances of  the  circulation  that  may  go  the  length  of  pallor  on  the  one  hand 
and  congestion  on  the  other  (constriction  or  dilatation  of  the  vessels),  along 
with  acceleration  or  slowing  of  the  heart's  action.  The  activity  of  the  heart 
and  the  behaviour  of  the  vessels  are,  however,  very  intimately  connected 
with  muscular  movements.  In  emotional  states,  physiognomic  attitudes, 
agitated  talk,  gestures  and  circulatory  disturbances  together  constitute  one 
expressive  whole,  and  accordingly  the  respective  cortical  fields  are  found 
situated  close  to  one  another  in  the  same  area,  so  close  indeed  that  one 
almost  runs  into  the  other. 

1  Cerevkov.      Uber  den  Einfluss  des  Gef assy  stem.     Karkov,  1892. 


EMOTIONS  AND  SENTIMENTS  267 

Not  only  have  we  respiration  and  circulation  but  indeed  all  the  viscera 
(the  organs  of  life)  represented  in  the  cerebral  mantle.  The  centre  for 
deglutition  has  also  very  close  relations  with  the  centre  of  respiration.1 

Bochefontaine,  Vulpian,  Fr.  Frank,  and  more  particularly  Bechterew,  in 
a  series  of  very  convincing  researches,  have  demonstrated  contractions  of 
the  spleen.  Movements  of  the  stomach  and  intestine  can  also  be  provoked 
by  excitation  of  a  small  area  of  the  cortex.  As  is  known,  movements  of  the 
cardiac  end  of  the  stomach  are  opposed  to  those  of  the  pylorus,  so  that 
opening  of  the  cardiac  end  coincides  with  contraction  of  the  pylorus.  When 
the  stomach  is  full  the  cardium  is  inactive  whilst  the  pylorus  is  active.  In 
the  cerebral  cortex  there  exists,  in  the  neighbourhood  of  the  crucial  sulcus, 
a  centre,  excitation  of  which  opens  the  cardiac  end  and  determines  con- 
traction of  the  pylorus.  This  area  is  situated  on  the  posterior  and  external 
part  of  the  sigmoid  gyrus.  Stimulation  of  the  antero-external  portion  of 
this  gyrus  determines  contraction  of  the  cardium  whilst  the  pyloric  region 
remains  in  a  state  of  rest. 

Bechterew  and  Mislawski 2  detected  points  on  the  sigmoid  gyrus  (median 
surface)  where  excitation  gave  rise  to  movements  of  the  vagina,  to  inhibition 
of  these  movements,  and  to  movements  of  the  uterus  (median  portion  of  the 
motor  zone) .  Bechterew  also  defined  a  small  area  on  .the  posterior  part  of 
the  sigmoid  gyrus  excitation  of  which  was  followed  by  increased  volume  of 
the  penis. 

One  cannot  fail  to  recognise  the  great  significance  of  these  investigations 
when  one  reflects  that  the  sexual  function,  although  directly  dependent  upon 
the  lower  centres,  has  also  its  representation  in  the  cerebral  mantle.  This 
anatomical  and  experimental  fact  may  explain  the  influence  exercised  by  the 
senses  of  sight,  hearing  and,  more  especially  in  the  human  subject,  touch, 
which  is  the  equivalent  of  smell  in  many  animals,  upon  the  excitation  of  the 
sexual  appetite  and  upon  the  imagination.  It  certainly  serves  to  explain 
certain  symptoms  observed  by  the  author  in  some  of  the  animals  he  experi- 
mented upon — e.g.  prolonged  erection  in  one  of  the  dogs  and  attempts  at 
copulation  in  several  monkeys.  The  investigations  in  question  prove  that 
a  lesion  in  the  neighbourhood  of  the  area  for  erection  may  cause  irritation 
therein  and  so  give  rise  to  erection  and  that  the  cortical  representation  of  the 
sexual  functions  is  located  behind  the  field  of  the  experiments  upon  the 
frontal  lobe.  In  the  higher  mammals  and  in  man  the  sexual  function  is  not 
a  blind  instinct  but  is  subject  to  the  control  of  the  will  and  to  conscious 
inhibition  just  like  the  vesical  function,  which  Mosso  and  Pellacani  maintain 
is  also  specially  represented  in  the  cerebral  cortex. 

Similarly,  the  movements  of  the  sphincter  of  the  anus  (co-ordinated  move- 
ments of  defsecation)  have  their  cortical  centre.  In  the  case  of  the  monkey, 
Sherrington  located  it  in  the  posterior  part  of  the  para-central  lobule,  for  he 
there  detected  a  small  circumscribed  area,  excitation  of  which  provoked 

1  Bechterew  and   Ostankow.     "  tlber   den    Einfluss   der   Gehirnrinde    auf   die 
Function  des  Schliickens  und  Atmens."     N enrol.  Centralblatt.     1894. 

2  Bechterew  and  Mislawski.     Loc.  cit. 


268  THE  MECHANISM  OF  THE  BRAIN 

movements  of  the  sphincter.  Others  have  located  the  said  centre  in  the 
posterior  convolution  of  the  sigmoid  gyms  at  some  distance  from  the  crucial 
sulcus. 

There  are  other  points  on  the  cerebral  cortex  where  excitation  produces 
marked  alterations  of  the  principal  secretions.  We  have  already  alluded 
to  Pavlov's  investigations  which  show  how  the  sight,  the  sound  and,  even 
more,  the  taste  of  a  food  substance  increases  the  secretion  of  saliva.  We 
know  that  fear,  on  the  other  hand,  dries  up  the  mouth.  Many  orators,  as 
they  commence  to  speak,  feel  the  mouth  becoming  parched.  We  are  familiar, 
too,  with  sialorrhoea  as  a  symptom  not  uncommon  in  dements.  Experi- 
mental investigation  has  afforded  an  interpretation  of  these  facts,  for 
faradisation  of  the  sigmoid  gyrus  provokes  increased  secretion  of  all  the 
salivary  glands,  especially  on  the  opposite  side  (Bochefontaine  and  Lepine), 
and  this  finding  is  in  no  way  minimised  by  the  fact  that  Bechterew  and 
Mislawski  point  to  a  small  area  on  the  fourth  external  convolution,  above  and 
in  front  of  the  fissure  of  Sylvius,  in  the  dog,  as  a  centre  of  greater  functional 
intensity  for  the  secretion  of  the  salivary  glands.  The  influence  of  mental 
excitement  upon  secretion  of  saliva  is  undoubted,  and  interesting  data  in 
this  connection  have  been  furnished  by  Malloizel.1 

Excitation  of  both  branches  of  the  sigmoid  gyrus  is  very  soon  followed 
by  abundant  flow  of  tears  from  both  eyes,  but  more  especially  from  that  on 
the  side  opposite  to  the  excited  hemisphere. 

Less  is  known  of  the  other  secretions,  but  the  researches  of  Bochefontaine, 
Pavlov,  Gerver,  S oilier,  and  especially  those  carried  out  throughout  a  period 
of  years  by  a  number  of  investigators  in  the  laboratory  of  Bechterew,  have 
furnished  interesting  data  regarding  the  modification  of  the  secretions  of 
the  liver,  pancreas,  stomach,  intestines,  kidneys  and  prostate,  as  the  result 
of  faradic  excitation  of  various  points  in  the  sigmoid  gyrus. 

The  secretion  of  the  mammary  glands  is  also  represented  on  the  sigmoid 
gyrus,  a  finding  which  confirms  the  old  and  popular  view,  supported  by 
clinical  observation,  that  powerful  emotion  arrests  the  secretion  of  milk  in 
woman,  or  so  modifies  the  chemistry  of  milk  as  to  induce  symptoms  of 
intoxication.  The  researches  of  Nikitin 2  dealing  with  the  area  of  excitation 
of  this  secretion  are  very  conclusive. 

One  can  foresee  that  all  the  glands  may  have  relations  with  the  cerebral 
mantle,  and  their  respective  secretions  must  therefore  possess  some  con- 
siderable significance  in  relation  to  the  other  functions  of  the  mantle,  in  this 
respect,  that  the  work  of  the  glands  is  subject  to  the  influence  of  emotional 
states,  and,  on  the  other  hand,  affects  the  condition  and  behaviour  of  the 
kinaesthesis,  modifying  what  we  call  the  humour  of  the  mind  (Stimmung 
of  the  Germans).  It  is  a  remarkable  fact  that  the  field  of  excitation  of 
all  the  glands  is  almost  entirely  circumscribed  within  the  tactile  zone 
(of  Flechsig)  which  comprises  the  two  convolutions  of  the  sigmoid  gyrus,  in 

1  Malloizel.     Comptes  rendus  de  la  Societe  de  Biologie.     1902. 

2  Nikitin.     "  "Ober  den  Einfluss  des  Gehirn  auf  die  Milchsekretion."      Verhandl. 
des  Wissens.  VersammL  des  Psych,  u.  Nervenk.     St  Petersburg,  1906. 


EMOTIONS  AND  SENTIMENTS  269 

dogs,  or  the  two  Kolandic  convolutions  in  monkeys  and  in  man,  along  with 
the  immediately  surrounding  parts — i.e.  the  same  area  as  that  which  contains 
the  points  of  excitation  for  the  respiration  and  circulation  as  well  as  that 
of  the  sensibility  and  the  musculature  of  the  whole  body. 

From  a  functional  point  of  view  this  region  of  the  cerebral  mantle  is  a 
very  complicated  one,  its  function  being  that  of  emotional  motor  reaction 
upon  the  external  world. 

The  frontal  lobe  does  not  participate  directly  in  this  very  fundamental 
function  of  life.  Emotion  is  the  psychic  equivalent  of  the  modifications 
(physical,  chemical,  mechanical)  induced  in  organisms  directly  by  external 
stimuli,  or  indirectly  through  the  psychic  self,  in  the  varying  vicissitudes 
of  the  physical  and  social  environment.  All  the  experimental  investigations 
warrant  us  in  excluding  the  frontal  lobe  from  the  complicated  mechanism 
of  those  emotional  manifestations  that  are  intimately  bound  up  with  the 
kinsesthesis.  Thus  it  happens  that  whilst  the  fundamental  emotions,  those 
of  self-preservation  and  defence,  closely  associated  with  all  the  representa- 
tions of  the  physical  self,  have  their  expressive  mechanism  in  the  tactile  and 
motor  zone  (somsesthetic  zone  of  Flechsig),  the  sentiments  which  arise  from 
inter-human  relations  emanate,  as  we  shall  presently  see,  from  another 
cortical  field. 

Hunger,  thirst,  the  sexual  need,  the  need  of  moving  about,  of  sleeping, 
of  avoiding  high  and  low  temperatures,  are  fundamental  emotions.  Hunger 
and  thirst  are  intimately  connected  with  material  interchange  and  the 
chemical  condition  of  the  various  cell-groups  of  which  the  organism  is  com- 
posed. The  sexual  appetite  has  probably  also  a  chemical  origin  if  the 
maturation  of  the  ovule  and  the  secretion  of  semen  are  to  be  considered 
chemical  facts.  Excessive  heat  and  excessive  cold  are  disintegrating,  and 
so,  in  the  course  of  various  civilisations,  a  series  of  provisions  for  protection 
against  these  has  arisen.  Possibly  some  emigrations  in  prehistoric  times 
were  determined  by  climatic  conditions  unsuitable  for  existence.  All 
sensations,  with  their  respective  appetites  or  repulsions  and  the  determinism 
towards  a  series  of  actions  calculated  to  satisfy  them,  may  be  included  in 
what  is  termed  by  some  the  instinct  of  self-preservation,  the  pleasure  of  living, 
the  will  to  live.  When  these  attitudes  of  mind  are  analysed,  we  find  in  all 
of  them  the  pleasure  of  satisfying  the  organic  needs,  more  especially  if  delay 
or  insufficiency  in  satisfying  them  bring  us  to  the  threshold  of  pain,  which 
is  an  expression  of  chemical  changes  taking  place  within  the  organism  owing 
to  insufficiency  of  nourishment,  dehydration,  etc. 

We  cannot  claim  to  know  what  chemical  modifications  of  the  organism, 
and  more  especially  of  the  nerve  cell,  induced  by  prolonged  rest,  give  rise 
to  the  impulse  to  move.  There  is  little  doubt,  however,  that  this  need, 
with  the  corresponding  pleasure  of  satisfying  it,  is  also  of  chemical  origin. 

The  need  for  sleep,  which  is  also  of  chemical  origin,  is  to  be  included 
amongst  the  fundamental  emotions,  the  chemical  modifications  here  con- 
cerned being  produced  by  the  work  of  the  senses  and  of  the  muscles,  by 


270  THE  MECHANISM  OF  THE  BEAIN 

suppression  of  light,  etc.  The  satisfaction  one  experiences  on  awakening 
from  a  refreshing  sleep  is  the  conscious  reflex  of  the  restored  chemical 
equilibrium  throughout  the  body,  especially  in  the  nervous  centres.  The 
pain  which  follows  nights  of  sleeplessness,  taking,  it  may  be,  the  form  of 
an  indefinite  feeling  of  malaise  and  bad  humour,  and  the  despair  that  may  go 
the  length  of  suicidal  emotion  in  individuals  who  suffer  from  severe  agrypnia, 
are  very  significant  proofs  of  the  fact  that  the  whole  organism,  but  more 
especially  the  brain,  takes  part  in  sleep,  which  is  a  fact  of  organic  integration. 
After  this  fundamental  group  comes  a  second  group  of  emotions  of  a 
higher  order,  such  as  fear,  joy,  anger,  etc.,  which  have  a  content  of  images 
that  are  to  a  much  larger  extent  extra -organic.  They  are  concerned  with 
the  ego  in  its  relations  with  the  outer  world,  and  have  a  much  richer  content 
of  images  and  a  wider  and  more  mutable  field  of  actions  and  reactions,  which 
are  outside  the  domain  of  the  fundamental  organic  needs,  and  reflect  rather 
the  ego  in  its  hedonistic  attitudes  and  impulses,  such  as  those  concerned 
with  the  avoidance  of  pain. 

A  constant  feature  of  the  more  intense  states  of  pleasure  and  of  pain  is 
the  marked  alteration  of  the  circulation,  respiration  and  secretions.  Now, 
these  functions  are  represented,  as  we  have  seen,  in  a  very  circumscribed  area, 
and  if  we  are  not  warranted  in  regarding  that  area  as  the  cortical  organ  of 
the  emotions,  we  are  at  least  justified  in  speaking  of  it  as  the  anatomical  field 
of  the  organic  reflexes  of  the  emotions.  Flechsig  was  of  opinion  that  all  the 
emotions  and  passions  accompanying  disturbances  of  the  circulation  and 
respiration  must  have  their  origin  and  seat  in  the  tactile  zone  which,  accord- 
ing to  him,  would  be  the  cortical  centre  of  the  sentiments  which  become 
conscious. 

Kirchhof? 1  accepts  this  view  with  but  slight  modification.  He  limits  the 
area  for  painful  sensations  to  that  tract  of  the  gyrus  f ornicatus,  on  the  internal 
aspect  of  the  hemisphere,  included  by  Flechsig  within  the  somaesthetic  zone. 

According  to  Flechsig,  the  somsesthetic  zone  comprises  the  motor  along 
with  the  tactile  zone,  and  contains  cells  the  axis- cylinder-prolongations  of 
which  either  directly  or  indirectly  reach  the  muscles  of  respiration,  the 
circulatory  apparatus  and  that  of  other  organic  functions,  so  that  functional 
disturbances  intimately  connected  with  the  emotions  and  instincts  thus 
become  conscious.  It  should,  however,  be  pointed  out  that  the  mechanism 
and  the  content  of  the  emotions  are  not  wholly  confined  to  the  anatomo- 
physiological  circle  of  the  tactile  zone. 

Evolved  emotion  is  a  state  of  consciousness  concomitant  with  those 
reflex  and  co-ordinated  phenomena  which  arise  from  perception  or  repre- 
sentation of  definite  objects  containing  elements  either  of  integration  or  of 
disintegration  of  the  organism,  in  the  widest  sense  of  the  terms — i.e.  in  both 
the  physical  and  the  psychic  sense.  The  two  primordial  forms  of  emotion 

1Kirchhoff.  "Neuere  Ansichten  uber  ortlichen  Grundlagen  geistiger  Storungen. 
Halle,  1896. 


EMOTIONS  AND  SENTIMENTS  271 

are  those  of  pleasure,  connected  with  all  that  leads  to  the  integration  or 
growth  of  the  organism  (physical  and  mental),  and  of  pain,  connected  with 
all  that  tends  towards  its  disintegration  or  diminution  (under  normal  con- 
ditions of  life) .  The  fundamental  law  is  that  every  stimulus  which  acts  upon 
us  modifies  the  ego  in  a  pleasurable  or  disagreeable  manner,  according  as  it 
furnishes  elements  that  are  assimilable  and  favourable  to  existence  or 
elements  that  are  disintegrating  or  hurtful  to  the  psycho -organic  unity. 

From  this  point  of  view  we  must  conclude  that  the  sensory  mantle  furnishes 
the  psychic  content  of  the  emotions,  whilst  the  tactile  zone  provides  the  organs 
of  their  cortical  reflexes. 

Broadly  speaking,  pain  may  be  interpreted  as  an  interference  with  the 
process  of  nutrition  in  the  organ,1  an  interpretation  which  corresponds,  in 
general,  with  the  fact  that  harmony  and  good  adaptation  are  on  the  line  of 
pleasure,  whilst  discord  and  faulty  adaptation  are  in  the  direction  of  pain. 
Adaptation  is  a  form  of  penetration  of  the  organism  into  its  environment, 
and  is  consequently  favourable  to  its  development. 

Pleasure  and  pain,  on  the  other  hand,  are  intimately  related  with  facility 
or  difficulty  in  the  biological  processes.  That  feeling  of  indifference  which 
all  have  experienced  as  the  result  of  fatigue,  has  its  origin,  according  to 
Hermann  and  Funke,  in  difficulty  of  the  psychic  and  reactive  processes. 
Fere  has  made  reference  to  the  uprising  of  the  arcanistic,  mystic  sense  of 
things  in  connection  with  depression  of  the  muscular  power.2 

Successful  psychic  functioning  (Meynert,  Gilmann) — i.e.  the  ready  re- 
presentation of  things,  and  facile  internal  motion  or  exteriorisation  in  order 
to  meet  the  requirements  of  life — coincides  with  pleasure,  whilst  obstacles, 
delay  and  resistance  are  on  the  threshold  of  pain.  A  need,  inclination  or 
tendency  always  implies  a  motor  innervation  to  some  extent  or  another 
(Kibot).  This  motor  innervation  is  pleasurable  or  disagreeable  according 
as  the  movement  is  completed  or  hindered. 

Hunger,  which  represents  an  organic  need,  is  a  pleasurable  sensation  if 
it  can  be  satisfied.  Many,  indeed,  are  afflicted  if  they  have  no  appetite 
and  yet  have  the  wherewithal  to  satisfy  it,  but  in  any  case  hunger  becomes 
a  painful  sensation  when  there  is  any  hindrance  to  its  satisfaction. 

The  same  psychological  process  has  a  painful  or  pleasant  resonance  in 
consciousness  according  as  the  accompanying  circumstances  are  unfavourable 
or  favourable. 

Pain  generates  unrest  and  a  tendency  to  flee  from  the  cause  of  it,  where 
circumstances  permit,  or  to  remove  all  that  hinders  or  afflicts  us.  In  this 
fact  (the  aversion  of  L.  Miller)  lies  the  mechanism  of  the  motor  reflex  or, 
in  other  words,  the  reaction,  which  assumes  as  many  forms  and  grades  as 
there  are  degrees  of  aversions. 

According  to  some  authorities,  amongst  them  Wundt  and  Ward,  pleasure 
and  pain  are  connected  with  a  higher  order  of  psychic  phenomena,  and  are 

1  Mead.     <VA  Theory  of  the  Emotions  from   the   Physiological  Standpoint." 
Amer.  Journ.  of  Psych.     1893-1895. 

2  Fere.     "  Pessirnisme  et  impuissance."     Rev.  Phil.     1886. 


272  THE  MECHANISM  OF  THE  BRAIN 

interpreted  in  terms  of  attention  to  the  particular  object.  Any  stimulus 
which  fails  to  awaken  some  degree  of  attention  is  "indifferent."  When 
attention  is  aroused,  one  of  two  things  may  happen  :  either  it  has  full  play 
without  any  hindrance,  in  which  case  we  get  a  state  of  pleasure,  or,  it  is 
disturbed  by  a  conscious  feeling  of  inhibition,  as,  e.g.,  in  the  case  of  obsessive 
ideas,  and  then  we  have  a  painful  feeling.  In  other  words,  attention  without 
hindrance  or  difficulty  is  on  the  threshold  of  pleasure,  whilst  pain  coincides 
with  obstructed  attention  (Sidney,  E.  Mezes).  All  states  of  intense  attention 
which  eventuate  in  clear  thought  or  in  efficacious  work  are  pleasurable, 
whilst  all  states  of  internal  conflict  accompanied  by  hesitation  and  practical 
difficulty  are  inefficacious  and  unpleasant. 

Physical  or  mental  activity  involving  the  expenditure  of  an  amount  of 
accumulated  force,  the  potential  of  which  when  resolved  into  actual  energy 
is  in  excess  of  what  the  stimulus  ordinarily  requires,  is,  according  to  Marshall, 
a  cause  of  pleasure,  whilst  the  psychic  state  connected  with  pain  is  got  when 
the  potential  of  energy  is  less  than  what  the  stimulus  habitually  requires, 
because  of  deficient  capacity  of  the  organs  from  which  it  emanates.  Pleasure 
and  pain  would  thus  be  primary  qualities  or  psychic  states  determined  by 
the  relations  between  activity  and  capacity  of  the  organs  of  consciousness, 
in  its  relations  with  the  world. 

H.  Spencer  puts  forward  the  view  that  pleasure  is  concomitant  with  all 
medium  activities.  Wundt  also  declares  that  in  all  the  sensory  spheres 
excitations  of  moderate  intensity  are  accompanied  by  feelings  of  pleasure, 
confirmation  of  this  being  afforded  by  the  fact,  already  brought  forward  by 
Ribot,  that  pleasure  carried  to  excess  or  over-prolonged  is  often  transformed 
into  the  opposite  condition.  What  best  suits  the  nerve,  says  the  eminent 
physiologist  Richet,  is  a  moderate  excitation  which  brings  its  activity  into 
play  without  tiring  it.1 

There  are  also  sensations  which  are  not  pleasurable,  yet  at  the  same  time 
are  not  really  painful.  These  are  ranged  in  a  scale  extending  from  indiffer- 
ence to  detachment,  and  differ  from  true  states  of  pain,  such  as  those  arising 
from  unsatisfied  desires,  inasmuch  as  the  psychic  correlative,  which  is  the 
experience  previously  acquired  and  brought  to  a  high  degree  of  tension  by 
repeated  attempts  at  satisfaction,  betrays  itself  in  obstructed  psycho-physical 
functioning.  Mention  has  been  made  of  indifferent  sensation  with  a  nascent 
tendency  to  withdrawal  or  to  approach  (Kulpe,  Marshall,  Kalkins),  but 
without  any  pleasant  or  disagreeable  emotion.  Strictly  speaking,  it  is  not 
so  much  a  question  of  indifference,  which  generally  is  due  to  habit,  but, 
rather,  that  we  have  here  to  deal  with  minimal  or  very  low  degrees  of  pleasure 
or  of  pain.  The  author  is  of  opinion  that  in  every  psychic  fact,  perceptive 
or  representative,  there  is  always  a  pleasant  or  unpleasant  emotional  tone. 
The  general  law  concerning  the  genesis  of  pain  may  be  summed  up  in  all 
those  relations  with  the  world  which  tend  to  disintegrate  the  nervous  element 
to  a  greater  extent  than  is  necessary  merely  to  overcome  obstacles.  This 
applies,  in  all  probability,  to  every  form  of  pain. 

1  Richet.     Rev.  scientifique.     190G. 


EMOTIONS  AND  SENTIMENTS  273 

The  author's  experiments  negative  Kalkins'  view 1  that  the  frontal  lobes 
are  the  chief  organs  of  the  fundamental  emotions  of  pleasure  and  of  pain. 
According  to  this  psychologist,  when  the  cells  of  the  frontal  lobes  are  well 
nourished  and  not  fatigued — in  other  words,  in  a  state  of  anabolism — they 
react  more  than  adequately  to  the  excitation  which  is  transmitted  from  the 
Rolandic  zone,  and  we  get  pleasure  ;  when,  on  the  contrary,  the  cells  of  the 
frontal  lobes  become  ill-nourished  and  exhausted — i.e.  when  they  are  in  a 
state  of  catabolism — they  react  inadequately  to  the  excitation  coming  from 
the  Rolandic  zone,  and  we  get  pain. 

It  seems  evident  from  a  brief  review  of  the  evidence,  even  if  we  take  into 
account  only  the  two  fundamental  tones  of  emotion,  that  we  are  not 
warranted  in  localising  the  emotions  in  any  definite  part  of  the  cerebral 
mantle,  as,  e.g.  in  the  tactile  zone.  To  this  area  we  attribute  no  greater 
significance  than  that  of  being  the  cortical  field  of  the  somatic  or  reactive 
reflexes  of  emotion.  Emotion  must  be  regarded  as  emanating  from  the 
whole  sensory  field,  so  far  as  its  representative  content  is  concerned,  and 
from  the  somaesthetic  zone,  so  far  as  the  respective  organic  reflexes  are 
concerned. 

We  have  seen  that  the  humour  of  the  mind  has  its  roots  in  the  kinaesthetic 
sense,  and  is  good  or  bad  according  as  all  parts  of  the  organism  function 
harmoniously  or  otherwise.  It  may  be  said  that  emotion  arises  from- any 
external  or  internal  fact  which  disturbs  the  kinaesthetic  equilibrium,  and 
tends  either  to  constrict  or  to  increase  the  psychic  personality,  to  oppose  it 
or  to  arrest  it  in  any  of  its  tendencies  or  conative  orientations  in  the  organic, 
intellectual  or  affective  spheres. 

Somatic  concomitants  of  pleasure  are  :  increased  circulation  in  the  head, 
volumetric  dilatation  of  the  peripheral  organs,2  heightening  of  the  pulse, 
acceleration  of  the  heart's  action,  radiant  visage  (or,  as  commonly  expressed, 
face  glowing  with  joy),  increased  depth  of  inspiration,  with  accelerated 
respiratory  rhythm  and  increase  of  muscular  power.  Pleasure  is  dynamo- 
genetic.3 

Somatic  concomitants  of  pain  are :  diminution  of  the  diameter  of  the 
vessels,  through  contraction  of  the  vascular  walls  ;  pallor  of  the  skin,  owing 
to  ischaemia  ;  diminution  of  certain  secretions — e.g.  the  mouth  becoming  dry 
and  the  milk  disappearing,  and  increase  of  certain  other  secretions,  such  as 
tears ;  constriction  of  the  pulmonary  vessels,  giving  rise  to  that  sense  of 
oppression  noticed  by  all  who  are  under  the  tyranny  of  pain  ;  feeling  of  cold, 
want  of  tone  in  the  voluntary  muscles,  whence  the  head  bowed  down  (bent 
with  sorrow,  as  Lange  says),  the  face  lengthened,  and  the  lower  jaw  slightly 
drooping ;  weakness  of  the  voice ;  enlargement  of  the  eyes,  with  wider 
opening  of  the  palpebral  fissures.  Pain  is  paralysing. 

The  fact  that  it  is  impossible  to  separate  the  mental  representations  from 

1  Kalkins.     An  Introduction  to  Psychology.     New  York,  1901. 

2  Lehmann.     Die  Hauptgesetzte  des  menschlichen  GefuhUlebens.     Leipzig,  1892. 

3  Fere.     Sensation  et  mouvement.     Paris.  1887. 


274  THE  MECHANISM  OF  THE  BRAIN 

the  somatic  concomitants  of  emotion  has  given  rise  to  two  opposite  theories 
concerning  the  nature  and  seat  of  the  emotions. 

According  to  one  theory,  emotion  consists  in  a  psychic  phenomenon 
determined  by  perceptions  or  by  ideas,  accompanied  by  a  number  of  somatic 
phenomena — vaso-motor,  muscular,  secretory,  respiratory — all  of  which 
are  consecutive  and  reflex.  According  to  the  other  theory,  emotion  is  con- 
stituted essentially  of  vaso-motor,  respiratory  and  general  somatic  pheno- 
mena, which  immediately  follow  perception  or  representation,  so  that 
alterations  in  the  various  functions,  transmitted  to  consciousness,  give  rise 
to  emotion.  According  to  the  latter  view  emotion  is  only  the  consciousness 
of  muscular  and  neuro-vascular  variations  taking  place  within  the  body. 
The  names  of  James,  Lange,  Sergi,  Pitres  and  Regis,  Soury,  Kulpe,  Mercier, 
Kalkins,  Irons,  Baldwin,  Dewey,  and  many  others,  are  connected  with  this 
disputed  question.  Here  is  what  James  says  :  "  Our  natural  way  of  thinking 
about  these  coarser  emotions  is  that  the  mental  perception  of  some  fact 
excites  the  mental  affection  called  the  emotion,  and  that  this  latter  state  of 
mind  gives  rise  to  the  bodily  expression.  My  theory,  on  the  contrary,  is 
that  the  bodily  changes  follow  directly  the  perception  of  the  exciting  fact,  and  that 
our  feeling  of  the  same  changes  as  they  occur  is  the  emotion.  Common-sense  says : 
We  lose  our  fortune,  are  sorry  and  weep ;  we  meet  a  bear,  are  frightened  and 
run  ;  we  are  insulted  by  a  rival,  are  angry  and  strike.  The  hypothesis  here 
to  be  defended  says  that  this  order  of  sequence  is  incorrect,  that  the  one 
mental  state  is  not  immediately  induced  by  the  other,  that  the  bodily  mani- 
festations must  first  be  interposed,  and  that  the  more  rational  statement  is 
that  we  feel  sorry  because  we  cry,  angry  because  we  strike,  afraid  because  we 
tremble,  and  not  that  we  cry,  we  strike,  or  tremble  because  we  are  sorry, 
angry,  or  fearful,  as  the  case  may  be.  Without  the  bodily  states  following 
on  the  perception,  the  latter  would  be  purely  cognitive  in  form,  pale,  colourless, 
destitute  of  emotional  warmth.  We  might  then  see  the  bear  and  judge  it 
best  to  run,  receive  the  insult  and  deem  it  right  to  strike,  but  we  should  not 
actually  feel  afraid  or  angry." 

Further  on  he  continues  :  "If  we  fancy  some  strong  emotion,  and  then 
try  to  abstract  from  our  consciousness  of  it  all  the  feelings  of  its  bodily 
symptoms,  we  find  we  have  nothing  left  behind,  no  '  mind  stuff '  out  of  which 
the  emotion  can  be  constituted,  and  that  a  cold  and  neutral  state  of  in- 
tellectual perception  is  all  that  remains.  ...  I  cannot  help  thinking  that 
all  who  rightly  apprehend  this  problem  will  agree  with  the  proposition  above 
laid  down.  What  kind  of  emotion  of  fear  would  be  left  if  the  f eeling  neither 
of  quickened  heart-beats  nor  of  shallow  breathing,  neither  of  trembling  lips, 
nor  of  weakened  limbs,  neither  of  goose-flesh  nor  of  visceral  stirrings,  were 
present,  it  is  quite  impossible  for  me  to  think.  Can  one  fancy  the  state  of 
rage  and  picture  no  ebullition  in  the  chest,  no  flushing  of  the  face,  no 
dilatation  of  the  nostrils,  no  clenching  of  the  teeth,  but  in  their  stead  limp 
muscles,  calm  breathing,  and  a  placid  face  ?  " 

If  one  could  demonstrate  that  motor,  vaso-motor,  and  secretory  pheno- 
mena, those  indeed  that  form  the  general  characteristic  of  emotion,  exist 


EMOTIONS  AND  SENTIMENTS  275 

apart  from  that  particular  psychic  state  concerned  in  the  emotions  of 
pleasure  and  pain,  whatever  be  their  forms,  the  organic  theory  of  the 
emotions  would  fall  to  the  ground.  When  we  consider  the  state  of  mind  in 
a  number  of  vaso-motor  disturbances  of  longer  or  shorter  duration,  finding 
there  nothing,  or  almost  nothing,  in  the  nature  of  true  emotional  states, 
we  feel  great  distrust  of  the  somatic  theory.  In  hysteria  we  frequently 
observe  cutaneous  ischaemia,  palpitation  of  the  heart,  respiratory  anxiety, 
while  the  subject  is  utterly  indifferent.  In  Basedow's  disease  we  meet  with 
a  great  increase  in  the  cutaneous  circulation,  redness  of  the  skin,  clear  and 
sparkling  eyes,  and,  instead  of  joy  or  anger,  a  sense  of  anguish  and  fear 
accompanies  those  somatic  phenomena.  Hysterical  women  with  anaesthetic 
skins,  with  ischaemia,  and  with  paralysis  of  a  great  number  of  their  muscles, 
are  very  far  from  showing  signs  of  sadness. 

The  cutaneous  ischaemia  and  the  trembling,  or  even  shaking,  which  we 
meet  with  in  malaria  do  not  give  rise  to  any  emotion,  if  we  leave  out  of  account 
the  general  feeling  of  malaise  inevitably  associated  with  the  disorder. 

Men  afflicted  with  polyneuritis,  with  complete  paralysis  and  muscular 
flaccidity,  sometimes  with  disappearance  of  all  the  muscular  masses,  are  for 
whole  days  in  excellent  humour,  if  only  they  are  allowed  to  hope  for  recovery. 

Grief  and  joy,  along  with  their  respective  physiognomic  attitudes  and 
modifications  of  respiration  and  of  the  pulse,  are  capable  of  being  simulated, 
but  in  this  case  the  corresponding  psychic  factor  is  absent;  indeed,  the  psychic 
content  may  be  entirely  different.  We  know  of  men  endowed  with  great 
self-possession  and  inhibitory  power  who  can  suppress  the  reflex  (organic) 
manifestations  of  great  joy  or  profound  grief. 

The  organic  theory  is  no  doubt  seductive  but  that  is  because  the  experi- 
mental habit  inclines  one  to  favour  the  doctrine  that  is  based  upon  objective 
and  demonstrable  facts. 

It  is  certain  that  between  the  first  psychic  fact  and  the  last  fact  of  emotion 
there  exist  links  that  follow  one  upon  another  in  consciousness,  in  the  form 
of  rapid  reasonings  and  imaginative  representations,  of  which  the  end  always 
is  that  the  ego  appears  to  be  either  compromised  or  exalted. 

In  the  writer's  opinion  the  weak  point  of  the  somatic  doctrine  lies  in  the 
fact  that  it  seeks  to  regard  the  somatic  phenomenon  as  playing  a  very 
substantial  part  in  the  mechanism  of  emotion,  whereas  the  truth  is  that  in 
the  disturbed  consciousness  there  always  co-exist  two  factors :  (a)  the  repre- 
sentation, along  with  the  internal  participation  of  the  ego  itself  ;  and  (6)  the 
somatic  factor.  Even  the  melancholic  in  his  grief  probes  his  imagination 
for  an  explanation  of  the  origin  of  his  trouble.  The  two  factors  are  in- 
separable. 

In  any  study  of  the  emotions  one  should  also  take  into  account  the  vital 
tone  of  the  individual.  There  is  no  doubt  a  normal  man,  in  perfect  health, 
is  not  troubled  at  the  thought  of  death.  Owing  to  the  uncertainty  of  the 
period  of  its  happening,  there  is  no  feeling  of  dread,  and  for  this  reason 
sailors  and  miners,  who  are  constantly  risking  their  lives,  have  no  fear  of 
death,  whilst  old  and  weak  persons  think  of  it  and  fear  it,  because  the  organic 


276  THE  MECHANISM  OF  THE  BKAIN 

sensation  of  the  weakness  of  their  bodies  is  in  harmony  with  the  idea  of 
death. 

The  favourable  acceptance  of  the  James-Lange  theory  is  due  to  the  fact 
that  we  cannot  demonstrate  a  subjective  state  of  emotion  dissociated  from 
somatic  phenomena,  whilst  only  the  latter  can  be  put  to  experimental  proof, 
as  exemplified  in  the  splendid  work  of  Mosso,  Lombroso  and  Patrizi  in  Italy. 
The  modern  scientific  spirit  attributes  value  only  to  such  facts  as  it  can 
control,  estimate  and  measure  objectively.  The  writer  cannot  get  away 
from  the  conviction  that  the  psychic  components  of  emotion  are  not  less 
important,  but  even  more  important,  than  the  somatic.  If  the  emotional 
tone  is  either  pleasurable  or  painful  that  is  because  consciousness  is  directly 
informed  of  the  emotion-producing  fact  which,  on  the  other  hand,  induces 
the  organic  reflexes. 

In  a  large  number  of  emotions  the  element  of  surprise  is  highly  important. 
If  a  soldier  on  the  march  comes  in  sight  of  the  enemy  and  is  assailed  by  fear 
of  death  and  the  pain  of  rapidly  imagined  wounds,  or  if  a  girl  is  terrified  on 
seeing  a  snake  close  to  her  feet  as  she  walks  along  a  country  path,  the  fear 
and  the  terror  in  these  cases  are  the  effects  of  a  psychic  factor,  that  of  surprise, 
which  interrupts  the  normal  course  of  the  representations  and  feelings,  these 
being  substituted  in  consciousness  by  others  that  have  a  disintegrating  power. 
It  is  the  imminent  threat  to  the  integrity  of  one's  own  physical  and  psychic 
personality  that  determines  that  complex  psycho-physical  state  which  we 
call  fear. 

If  the  girl  sees  the  serpent  from  afar,  and  is  not  threatened,  or  if  the 
soldier  has  already  seen  the  enemy  several  times,  so  that  there  is  no  surprise, 
and  danger  appears  less  imminent,  or,  even  should  it  be  imminent,  if  the 
consciousness  has  previously  been  occupied  by  those  images  and  dangers  so 
often  that  the  personality  has  become  accustomed  to  them ;  if  there  is 
adaptation  of  the  consciousness  to  the  new  order  of  images — as  happens  in 
the  case  of  miners  and  sailors — the  emotion  "  fear  "  either  is  insignificant  or 
is  a  simple  reminiscence  of  what  it  was  on  the  first  occasion. 

Between  perception  or  representation  and  the  organic  phenomena  of 
emotion  there  exists  a  complex  psychic  factor,  which  in  its  essence  can  be 
reduced  either  to  a  threat  of  disintegration  (pain),  to  interdiction,  or,  on 
the  Other  hand,  to  instantaneous  exaltation  of  the  personality.  If  a  man 
striving  for  a  fortune  acquires  it  gradually,  by  adequate  means  and  methods, 
he  will  not  have  any  emotion  of  joy.  His  consciousness  gradually  integrates 
itself  with  the  image  of  the  million,  and  his  internal  satisfaction  becomes  a 
feature,  a  permanent  attribute,  of  the  progressive  adaptation  of  his  person- 
ality to  the  new  conditions  of  existence.  Such  internal  satisfaction  is  not 
an  emotion,  it  is  a  state. 

If,  on  the  other  hand,  even  a  modest  fortune  should  come  to  him  suddenly 
— as,  e.g.,  the  winning  of  a  prize  in  a  lottery — his  joy  might  be  so  intense  that 
he  would  run  the  risk  of  a  congestive  attack  or  a  cerebral  apoplexy.  In  this 
case  it  is  surprise  that  breaks  up  the  habit  of  the  consciousness  and  deter 
mines  the  emotion.  Two  factors — the  person  and  the  fortune— remain  the 


EMOTIONS  AND  SENTIMENTS  277 

same  ;  the  third — the  duration  of  the  representation,  which  if  brief  gives  rise 
to  surprise,  if  prolonged  or  repeated  creates  a  habit  of  consciousness — is 
variable.  One  might,  in  many  cases,  picture  this  phenomenon  to  oneself 
as  a  sudden  and  abrupt  reversing  of  the  machinery  of  the  cerebral  waves, 
after  the  mechanism  is  all  ready  to  start,  or  has  already  acquired  motion, 
in  a  particular  direction.  One  may  suggest  that  the  high  nervous  tension 
produced  by  the  surprise  that  interrupts  the  normal  course  of  thought,  while 
it  interdicts  the  higher  centres  (reasoning  and  attention),  discharges  itself 
upon  the  lower  organic  centres,  and  determines  the  reflex  organic  phenomena 
of  emotion.  Let  us  eliminate  surprise,  give  free  course  to  thought,  and 
direct  our  attention  to  the  sensation  that  has  produced  the  emotion,  and,  as 
Stratton  has  observed,  the  emotion  ceases  or  becomes  markedly  lessened. 

Where  an  individual  places  himself  voluntarily  in  circumstances  that 
occasion  emotion,  as  in  the  case  of  the  orator  who  has  prepared  his  speech, 
or  that  of  the  traveller  who  passes  along  deserted  ways  by  night,  the  real 
cause  of  the  emotion  is  to  be  found  in  the  conflict  that  takes  place  between 
the  sentiments  and  impulses  that  determine  him  to  speak  or  to  travel,  and 
other  sentiments  and  impulses  that  threaten  to  compromise  the  ego.  If 
the  orator  were  sure  of  himself  and  of  the  opinion  that  others  would  express 
about  him,  and  if  he  did  not  contemplate  the  possibility  of  compromising 
some  of  the  components  of  his  personality  (self-esteem,  ambition),  then  he 
would  not  be  perturbed,  just  as  the  traveller  would  not  be  perturbed  if  he 
did  not  know  that  he  was  exposed  to  danger.  In  these  cases  the  pain  or 
fear  arises  from  the  contrast  between  the  tendency  of  the  ego  to  affirm  itself 
and  the  danger  of  an  opposite  result.  The  respiratory  anxiety  and  the 
tumultuous  action  of  the  heart  are  reflexes  of  these  representations  which 
compromise  the  ego,  and  do  not  in  themselves  constitute  the  state  of  conscious 
fear.  In  ereutophobia,  or  the  fear  of  blushing,  the  principal  and  prepon- 
derating element  is  the  idea  of  blushing ;  this  it  is  which  determines  or 
provokes  emotion.  It  is  the  fear  and  presumption  that  others  are  detecting 
in  the  redness  of  the  face  some  hidden  cause,  and  drawing  inferences  there- 
from of  a  compromising  nature.  The  situation  becomes  so  desperate  that 
finally  the  sufferer  will  only  leave  the  house  at  night-time,  so  that  the 
reddening  may  not  be  observed.  Yet  how  often  does  it  happen  that  flushings 
of  the  face  and  head  take  place  without  in  any  way  disturbing  the  con- 
sciousness !  The  fact  is  that  phenomena  of  vaso-constriction  and  vaso- 
dilatation,  associated  with  disturbances  of  respiration,  are  observed  in 
many  debilitated  persons,  especially  in  young  girls,  without  their  being 
aware  of  any  of  those  modifications  which  emotion  induces  in  the  conscious- 
ness. The  young  person  who  suffers  from  ereutophobia  has  been  subject 
for  some  time  past  to  reddening  of  the  face  and  rush  of  blood  to  the 
head,  but  has  not  experienced  any  emotional  fear  of  blushing  until  on  some 
occasion  she  has  been  informed  by  others  or  has  seen  herself  and  begun  to 
imagine  that  others  are  noticing  the  blush  and  indulging  in  suspicions  which 
compromise  her  respectability. 

Those  who  suffer  from  hemiplegia  due  to  a  lesion  so  situated  that  it 


278  THE  MECHANISM  OF  THE  BRAIN 

withdraws  the  optic  thalamus  from  the  inhibiting  influence  of  certain  parts  of 
the  cerebral  mantle,  or  allows  abnormal  stimulation  of  the  thalamus,  present 
the  outward  appearance  of  great  emotivity.  They  weep,  laugh,  and  cry  out 
on  the  slightest  impression ;  yet  it  is  evident  that  there  is  no  true  emotion, 
only  the  semblance  of  it.1  The  weeping  and  laughter  of  such  sufferers  are 
only  simulacra  of  the  real  emotions  and  if  there  is  any  emotional  resonance  of 
these  in  the  consciousness  it  has  to  be  attributed  to  old  and  repeated  associa- 
tion between  the  somatic  phenomena  and  the  respective  emotional  states. 

In  the  ordinary  chorea  of  Sydenham,  if  the  affection  is  severe  enough 
to  involve  the  musculature  of  the  face  in  the  anarchy  of  the  muscles  of 
the  trunk  and  limbs,  the  physiognomy  assumes  the  strangest  expressions 
of  hatred,  anger,  menace,  pain  or  joy,  while  the  mind  gives  no  evidence, 
through  corresponding  commotion,  of  sharing  in  the  emotion  expressed  by 
the  physiognomy. 

We  know  how  abundant  secretion  of  tears,  with  red  and  swollen  face, 
reddened  eyes,  and  increased  secretion  of  nasal  mucus — all  symptoms  denot- 
ing dilatation  of  the  vessels  of  the  skin,  the  face  and  the  mucous  membranes 
— sometimes  coincide  with  pain.  Lange  supposes  that  these  symptoms 
are  consecutive,  of  the  nature  of  a  reaction  against  the  primary  constriction 
— a  relaxation  of  the  small  arteries  after  strong  contraction.  It  remains 
an  open  question,  however,  whether  pain  and  anguish  are  accompanied  by 
vascular  constriction,  even  of  short  duration,  or  whether  it  is  not  rather  the 
case  that  the  vascular  reaction  varies  in  different  subjects.  The  writer's 
experience  leads  him  to  conclude  that  pain  is  not  constantly  associated  with 
vascular  constriction. 

Rehmka 2  in  recent  times  has  brought  forward  a  wealth  of  facts  in  support 
of  the  view  that  sentiment  is  a  subjective  fact,  while  the  representation  is 
objective.  The  sentiment  is  determined  by  a  group  of  images,  either  distinct 
or  obscure,  which  constitute  the  objective  feature  of  a  particular  conscious- 
ness. The  mode  of  feeling,  be  it  pleasant  or  disagreeable,  thus  depends  on 
the  image  which  falls  into  the  focal  point  of  attention. 

Mantegazza,who  undeniably  was  a  keen  observer,  remarks  in  the  Physiology 
of  Pleasure  and  Pain  3  that  painful  stimuli  sometimes  reduce  the  heart's 
action  and  sometimes  increase  it,  whilst  they  cause  respiration  to  be  some- 
times more  frequent  and  shallow,  sometimes  slower  and  deeper.  This 
statement  holds  good  in  the  case  of  the  movements  that  an  animal  makes 
under  conditions  that  are  painful — as  in  flight,  for  example.  It  is  no  doubt 
true  that  these  movements  are,  as  it  were,  spasmodic,  in  one  sole  direction, 
as  remarked  by  Ribot,4  and  that  in  its  ultimate  analysis  pain  is  accompanied 
by  diminution  of  muscular  energy.  Yet  it  is  indisputable  that  the  conscious 
fact  of  pain  or  fear  sometimes  coincides  with  phenomena  that  are  opposite 
in  nature  to  those  upon  which  it  has  been  said  to  depend. 

1  T.  Senise.    II  riso.    Naples,  1914. 

2  Rehmka.     Zur  Lehre  vom  Gemut.    Leipzig,  1911. 

3  Mantegazza.    Fisiologia  del  dolor e  e  del  piacere.     1879. 

4  Ribot.     PsycTiologie  des  sentiments.     1896. 


EMOTIONS  AND  SENTIMENTS  279 

The  assertion  of  Miinsterberg  that  agreeable  stimuli  produce  movements 
of  extension  and  disagreeable  stimuli  movements  of  flexion  has  been  only 
partly  confirmed  by  the  experiments  of  Dearborn  and  Spindler.1  These 
authors  have  found  that  the  reaction  varies  according  to  the  nature  and 
temperament  of  each  individual,  some  making  movements  of  extension 
mostly,  others  those  of  flexion,  whether  the  stimulus  be  pleasant  or  un- 
pleasant. Under  the  influence  of  painful  stimuli  the  flexions  were  found 
to  be  66-6  per  cent,  and  the  extensions  33-3  per  cent.  On  the  other  hand, 
under  agreeable  stimuli  the  extensions  were  67-8  per  cent,  and  the  flexions 
32-2  per  cent. 

Objective  language  is  the  physical  component  of  thought  just  as  the 
somatic  phenomena  described  are  the  physical  component  of  emotion.  Take 
the  case  of  an  individual  who  has  become  aphasic  as  the  result  of  a  lesion 
of  the  cortical  motor  centre  (so  that  he  suffers  from  true  motor  aphasia  and 
represents  to  himself  the  images  of  things  and  the  respective  words,  but  is 
unable  to  translate  them  into  motor  images  and  hence  into  co-ordinated 
movements  for  the  articulation  of  the  words) :  if  he  does  not  express  his 
thought  because  it  lacks  the  physical  component  that  is  indispensable  for  its 
extrinsication,  no  one  will  think  that  thought  rests  upon  that  component 
of  language,  and  that  the  anatomical  basis  of  language,  in  its  motor  com- 
ponent, is  the  same  as  that  of  thought.  Such  a  view  is  applicable  to  the 
sensory  images  of  words,  as  mentioned  in  the  preceding  chapters. 

If  we  adopt  the  formula  preferred  by  the  upholders  of  the  somatic  theory 
of  emotion  we  shall  have  to  say :  "  I  see  such  a  thing ;  I  name  it,  therefore 
I  perceive  it."  "  I  represent  to  myself  certain  images  ;  these  are  reflected 
on  the  centres  of  speech,  which  then  furnishes  me  with  the  notion  of  things." 
Surely  reasoning  such  as  this  will  not  be  adopted  by  any  psychologist. 

In  some  cases — e.g.  degenerates — emotions  of  joy  are  expressed  by  mimicry 
of  weeping.  A  lady  mentioned  by  Sikorsky  used  to  smile  in  such  a  way 
that  it  was  always  uncertain  whether  she  were  laughing  or  weeping.  She 
had  no  other  mimicry.  In  progressive  paralysis  and  in  hallucinatory  paranoia 
we  often  find  so-called  indifferent  mimicry  associated  with  different  emotional 
states,  or  we  meet  with  laughter  and  weeping  without  emotional  content. 

Ferrari 2  remarks  appropriately  that  cognition  of  the  organic  modifica- 
tions (vascular,  glandular,  etc.),  as  they  are  noticed  by  the  consciousness, 
does  not  give  rise,  as  James  says,  to  emotion.  He  adopts  Langley's  view 
as  to  the  sympathetic  and  its  three  divisions,  the  cerebral  autonomic  system, 
the  sacral  autonomic  system,  and  also  the  spinal  (visceral)  system,  and 
speaks  of  the  emotional  reaction  as  belonging  to  the  sympathetic  system. 
The  emotional  reflex  becomes  moderated  by  the  progressive  development 
of  the  cerebrum  with  its  inhibitory  powers  (cognition). 

Organic  manifestations  of  emotion  and  consciousness  are  two  factors 
that  are  closely  bound  up  with  one  another,  but,  at  the  same  time,  one  must 

1  Dearborn    and    Spindler.     "Involuntary   Motor   Reaction   to    Pleasant    and 
Unpleasant  Stimuli."     Psych.  Rev.     1897. 

2  Ferrari.     "  Le  emozioni  e  la  vita  del  subcosciente."     Riv.  di  Psic.     1912.. 


280  THE  MECHANISM  OF  THE  BRAIN 

insist  upon  the  fact  that  emotional  manifestations  may  occur  without  any 
consciousness  of  emotion. 

Another  question  presents  itself  to  us  at  this  point:  "Do  the  funda- 
mental emotions  differ  from  sentiments  ?  If  so,  wherein  lies  the  difference 
between  these  two  very  important  facts  of  mental  life  ?  " 

Lange  distinguishes  the  group  of  emotions  from  that  of  sentiments  by 
the  fact  that  sentiments  are  not  accompanied  by  the  organic  phenomena 
attached  to  the  emotions.  One  cannot  altogether  agree  with  this  sharp 
distinction  of  Lange,  as  regards  the  essential  features  of  the  two  groups, 
especially  if  it  be  remembered  that  he  has  been  induced  to  make  this  dis- 
tinction by  the  necessity  of  maintaining  his  theory  of  emotion.  He  says : 
"  It  is  incontestable  that  sadness,  joy,  fear,  anger,  and  other  similar  states 
constitute  a  group  of  phenomena  distinct  from  love,  hatred,  contempt,  and 
admiration,  and  from  the  psychological  point  of  view  it  is  necessary  to 
separate  them.  It  is  only  to  the  first  group  that  I  apply  the  term  '  emotion ' ; 
the  other  states  are  passions,  sentiments,  or  whatever  one  chooses  to  call 
them.  .  .  .  As  a  matter  of  fact  it  becomes  absolutely  necessary  for  anyone 
who  studies  the  physiology  of  these  phenomena  to  distinguish  them  as  far 
as  possible.  We  cannot  assimilate  things  so  different  as  terror,  fury,  joy, 
envy,  love,  and  the  passion  for  liberty." 1 

It  is  difficult  to  demonstrate  any  distinction  in  the  real  nature  of  the  two 
groups.  Indeed,  everything  induces  us  to  believe  that  the  states  of  the 
second  group  represent  only  advanced  degrees  of  those  of  the  first.  More 
advanced  evolution  means  that  new  components  have  been  united  to  and 
assimilated  with  the  first,  but  that  does  hot  change  their  intimate  nature 
or  their  origin.  The  same  thing  happens  with  emotions  as  with  ideas.  If 
from  the  simple  images  of  herbs,  fruits  and  flesh,  with"  which  we  satisfy  the 
sense  of  hunger  and  sustain  ourselves,  we  have  come  to  form  the  concept  of 
food  in  association  with  that  of  preservation — it  may  be,  perhaps,  through 
the  intervention  of  reflection,  although  this  is  very  doubtful — that  does  not 
establish  essential  differences  between  separate  foods  and  food  in  general. 

So,  too,  the  primitive  satisfaction  of  hunger  gradually  becomes  pene- 
trated by  the  joy  of  labour,  associated  with  the  sentiment  of  the  duty  of 
working ;  into  these  there  enter  as  components  all  the  pleasures  that  arise 
from  difficulties  overcome  and  from  the  successful  extrinsication  of  our 
increasing  activities,  as  well  as  all  those  that  come  from  the  labour  of  others 
and  from  the  beneficent  current  of  solidarity  that  smooths  away  so  many 
troubles  in  life,  bringing  additional  comforts  and  giving  fresh  impulses  to 
new  and  more  harmonious  forms  of  existence. 

These  new  components,  through  which  the  primitive  movements  for 
securing  food  have  been  transformed  into  others,  more  complex  and  more 
combined,  do  not  alter  the  intimate  emotional  nature  of  those  states. 
Pleasure  and  pain  are  ever  the  watchful  sentries  which  determine  and 
co-ordinate  the  actions  of  human  beings. 

1  Lange.     "  Les  emotions."     fitude  psychophysiologique. 


EMOTIONS  AND  SENTIMENTS  281 

More  complex  representations,  new  desires,  new  motor  tendencies,  and 
new  aspirations,  corresponding  to  the  ever-increasing  capital  of  ideas  and 
notions  of  the  world  and  of  the  relations  of  each  individual  therewith,  do 
not  alter  the  real  nature  of  the  struggle/or  pleasure  and  against  pain.  On  the 
other  hand,  with  the  suppression  of  many  of  the  old  motor  tendencies  the 
mode  of  satisfying  the  appetites  has  become  complicated,  but  the  essential 
nature  of  these  has  in  no  way  been  altered.  Thus,  through  continuous 
grafting  of  emotional  and  intellectual  components,  the  old  emotion  of 
hunger  that  formerly  excited  simple  reflexes  has  given  place  to  the  elevated 
sentiment  of  the  duty  of  labour,  which  in  its  turn  generates  reflexes  of 
extreme  complication  in  an  endeavour  to  secure  greater  comfort  in  life. 

Even  the  religious  sentiment,  patriotism,  the  moral  sentiment,  love,  in 
the  widest  sense  of  the  term,  including  love  of  liberty,  of  art  and  of  science, 
all  present  the  same  fundamental  characters.  Analysis  of  these  sentiments 
provides  an  incontestable  proof  of  the  tendency  of  the  psychic  ego  towards 
progressive  development,  towards  integration  and  towards  the  consumma- 
tion of  its  aspirations.  At  one  moment  we  behold  it  rising  towards  the 
sublime  and  divine ;  again,  we  see  it  penetrating  the  spirit  of  the  ethnic 
group  to  which  it  belongs  and,  in  the  illusion  of  representing  that  group, 
seeking  to  synthetise  in  itself  the  emotions  and  sentiments  of  the  group,  be- 
stirring itself  for  the  happiness  of  all,  even  at  the  cost  of  self-sacrifice ;  and 
yet  again,  we  find  it  assimilating  the  mind  of  another  being  whose  vibrations 
increase,  perhaps  a  hundredfold,  its  joy  in  life  and  its  activities  in  any 
direction  or  form  of  labour.  It  is  always  the  ego,  in  its  hedonistic  orientation, 
which  exercises,  consciously  or  unconsciously,  a  great  power  of  assimilation 
both  in  the  physical  world  (cognition)  and  in  the  social  world. 

The  higher  sentiments  do  not  involve  the  field  of  the  organic  reflexes 
of  emotions,  of  which  we  have  spoken.  They  reflect  the  psychic  ego  more 
particularly,  drawing  their  elements  from  the  cosmic  and  social  environ- 
ment, and  inciting  mankind  to  actions  which  are  to  be  considered  as  a  wider 
reflex,  the  equivalent  of  the  organic  reflexes  of  the  primitive  emotions. 
Analysis  shows  the  presence  in  their  structure  of  numerous  intellectual 
elements  in  logical  connection.  These  intellectual  components,  associated 
as  they  are  with  various  corresponding  affective  dispositions  of  the  ego,  do 
not  bring  into  action,  except  in  a  very  slight,  perhaps  imperceptible,  degree, 
the  centres  of  organic  innervation  which  come  into  play  in  those  primitive 
emotions  more  closely  connected  with  the  organic  ego,  but  they  are  reflected, 
directly  or  indirectly  (through  other  logical  series  of  thoughts),  in  human 
conduct,  considered  in  the  widest  sense  of  the  term. 

Sentiments,  like  the  primary  emotions,  have  their  roots  in  the  kinsesthesis, 
inasmuch  as  this  is  the  essential  nucleus  of  the  personality.  There  is  no 
sentiment  that  is  not  prepared  in  this  subsoil.  This  it  is  which  gives  an 
individual  his  emotional  sensibility,  participating  perhaps  in  the  mechan- 
ism of  expression  and  giving  an  emotional  colouring  and  direction  to  the 
intellectual  representations. 

Emotions   and   sentiments,   indeed,   are   merely  degrees    of    states   of 


282  THE  MECHANISM  OF  THE  BRAIN 

consciousness,  with  more  or  less  conscious  reflexes.  First  in  the  series  conies 
the  fundamental  sensation  of  pleasure  or  pain  which  simple  stimuli  produce 
when  they  come  into  contact  with  the  body  and  penetrate  the  kinaesthetic 
sense.  Last  in  the  series  are  the  higher  sentiments,  those  which,  in  the  moral 
and  intellectual  field,  accompany  the  hazards  of  life  within  the  environment. 
This  evolution  takes  place  by  the  progressive  addition  and  fusion  of  new 
components,  these  being  furnished  by  the  relations  of  each  individual  with 
others,  and  by  the  experience  of  these  relations. 

The  same  evolutionary  process  is  to  be  followed  in  the  case  of  the 
sentiments  as  in  that  of  intelligence. 

In  well-evolved  beings  thought  and  sentiment  are  in  harmonious  com- 
bination. This  may  be  said  both  of  men  and  of  races.  In  some  men  there 
prevails  that  force  which  determines  sentiment ;  in  others  that  which  is 
productive  of  calculating  thought.  Where  cold  thought  prevails  over  senti- 
ment, conduct  is  generally  egoistic,  and  this  is  true  both  of  the  individual 
and  of  the  group.  Bergson,  perhaps  by  way  of  protest  against  the  Germanic 
mentality,  asserted  that  life  is  not  merely  thought  (Kultur)  but  something 
much  more  profound — sentiment.  In  the  evolution  of  sentiment  the 
altruistic  element  becomes  more  pronounced.  Normal  mental  life,  at  its 
highest  level,  presents  a  harmony  between  thought  and  sentiment.  Regnaud l 
compares  mental  life  with  a  straight  line,  the  extremes  of  which  represent 
thought  and  sentiment.  The  middle  of  the  line  coincides  with  equilibrium 
between  the  former  and  the  latter.  When  sentiment  prevails  and  assumes 
the  control  and  direction  of  conduct,  the  regulating  power  of  thought  is 
encroached  upon  or  made  subservient.  Where,  however,  thought  or  cold 
calculation,  without  any  sentimental  tone  except  the  egoistic,  directs  or 
regulates  human  actions,  conduct  becomes  directed  towards  the  satisfaction 
and  consummation  of  selfish  aims,  without  consideration  of  the  interests  of 
others,  and  leads  even  to  criminality,  individual  or  collective. 

Yet  emotion  or  sentiment  always  does  accompany  the  intellectual  pro- 
cesses, inciting,  encouraging  and  animating  them,  infusing  into  them  the 
breath  of  interest.  Even  the  most  austere  scientific  research  is  imbued  with 
the  joy  of  truth,  just  as  a  social  and  political  situation  reveals  the  high  national 
interest  which  pervades  the  soul  of  the  statesman  who  courageously  con- 
fronts the  difficulties  opposed  to  him.  It  is  emotion  that  impels  to  new 
thoughts  and  gives  rise  to  man's  restless  activity.  That  it  is  which  promotes 
or  creates  interest,  which  exalts  or  depresses.  Through  this  we  are  led  to 
experience  the  whole  gamut  of  pleasure  and  of  pain ;  this  it  is  which  awakens 
all  the  hidden  energies  of  the  human  spirit  and  lets  fly  from  the  anvil  the 
spark  of  genius.  The  artist,  the  scientist,  the  hero,  the  politician,  the  man 
of  the  mart,  the  workshop  or  the  field,  men,  indeed,  engaged  in  all  civil 
occupations,  and  works  of  progress,  are  inspired  by  ideas  but  moved  by 
sentiment,  which  is  the  real  goad  that  excites  the  ego,  as  man  makes  his  essay 
in  the  struggle  for  life  and  victory.  Emotion  is  like  the  sound  of  a  stringed 
1  Regnaud.  Origine  et  philosophie  de  langage.  1888. 


EMOTIONS  AND  SENTIMENTS  283 

instrument  from  which  the  bow  draws  vibrations,  ranging  from  the  widest 
to  the  shortest  and  most  acute,  producing  all  the  tones  and  symbolising 
the  infinitely  various  states  of  the  human  mind,  as  it  thinks,  feels  and  acts. 
From  timidity  to  bold  assurance,  from  doubt  to  positive  assertion,  from 
fearful  indifference  to  audacious  desire,  from  aesthetic  to  moral  pleasure, 
from  love,  which  is  penetration  of  minds,  to  repellent  hatred,  from  fear  which 
disarms  to  courage  which  confronts,  from  diffidence  which  hinders  to  faith 
which  emboldens,  from  vanity  to  ambition,  from  need  of  the  essential,  which 
spurs  one  on,  to  enjoyment  of  accumulated  fortune  which  allows  its  possessor 
to  take  life  easily  and  permits  the  commencement  of  decadence,  from  love 
for  others  to  the  tyranny  of  an  exacting  and  rapacious  egoist — all  these 
and  other  multiform  states  confer  a  particular  tone  and  impress  a  particular 
directive  upon  life. 

Desire,  to  some  psychologists,  is  the  turn-key  of  psychic  life:  it  is 
fundamental;  it  stimulates  thought,  which  in  turn  furnishes  plans  for  its 
satisfaction. 

At  the  same  time  it  is  true  that  it  is  often  the  intellect  that  discovers  new 
horizons,  opening  up  new  fields  to  desire  and  human  activity.  Appetite,  as 
Spinoza  observed,  is  the  very  essence  of  man,  and  from  it  is  derived  all  that 
seems  to  preserve  him.  Intellect  offers  motives  but  not  the  determinism, 
the  impulse  to  action.  Desire  it  is  that  urges  to  action,  and  that  is  emotion. 
Reason  is  inhibitive  rather  than  propulsive  and,  from  a  psychological  point 
of  view,  it  would  be  absurd,  as  Ribot  remarked,  to  suppose  that  an  arid  idea, 
a  conception  devoid  of  any  emotional  accompaniment,  can  have  the  slightest 
influence  upon  human  conduct.  Reason,  says  Schopenhauer,  does  not  as 
a  rule  make  use  of  the  passions ;  rather  do  passions  make  use  of  reason  to 
attain  their  ends. 

Knowledge  (culture)  exalts  man,  placing  him  in  a  higher  sphere  in  which 
he  intuitively  perceives  a  form  of  dominion  with  respect  to  others  (ambition) 
(Sherrington). 

The  writer  has  no  desire  to  discuss  the  question  whether  or  not  there  are 
such  things  as  ideas  devoid  of  any  emotional  colouring,  but  he  expresses 
the  opinion  that  wherever  there  is  an  order  of  ideas  which  resolve 
themselves  into  actions,  wherever  the  ego  is  caught  in  the  motion  of 
things  and  in  the  conflict  of  individual,  social,  scientific,  religious, 
aesthetic,  interests,  it  is  always  emotion  that  is  the  great  multiplier  of 
the  energies,  the  vivifier  of  thought,  the  propulsive  force  which  incites  and 
determines. 

It  is  not  thought  that  controls  sentiment,  rather  does  the  latter  guide 
thought,  and  where  it  would  appear  that  reason  inhibits  or  controls,  it  will 
often  be  found  that  there  is  really  another  sentiment  controlling  the  first, 
which  is  only  in  appearance  the  more  propulsive.  It  is  interest  which  gives 
value  to  the  intellectual  content  of  a  man  or  a  nation. 

The  exercise  of  intelligence  and  memory  enlarges  the  field  of  the 
emotions  and  sentiments  (desire)  and,  consequently,  the  field  of  action; 
but  emotion  and  sentiment  account  for  a  large  part  of  the  story 


284  THE  MECHANISM  OF  THE  BRAIN 

of  humanity  (all  wars  have  had  the  way  prepared  for  them  by  desire  for 
dominion,  for  wealth,  for  liberty,  or  by  religious  sentiment  or  the  influence 
of  woman). 

If  emotion  exceeds  certain  limits,  the  greater  intensity  is  at  the  expense 
and  to  the  detriment  of  intellect.  The  mental  fields  become  restricted,  the 
horizons  obscure,  the  associative  power  enfeebled,  and  the  flow  of  ideas 
retarded.  Again,  if  emotion  is  so  strong  as  to  reach  the  degree  of  passion, 
this  encroaches  on  the  logical  power  and  lays  siege  to  the  mental  capital, 
paralysing  the  evocative  and  associative  powers  which  are  the  factors  of 
logic,  and  establishing  the  wasteful,  static  condition  of  a  mind  disarmed. 
Passion  detains  in  the  focal  point  of  consciousness  only  those  particular 
ideas  and  images  from  which  it  draws  its  origin :  they  are  its  objective. 
If  other  ideas  do  cross  the  field  of  consciousness,  they  are  feeble  and  void 
of  determinative  capacity ;  as  no  interest  animates  them  they  succumb  to 
the  domination  of  ideas  enlivened  and  protected  by  powerful  passion. 
Passion  is,  at  bottom,  only  an  acute  or  chronic  emotion  which  disturbs  the 
intellect  in  various  degrees,  impairing  its  vigour,  controlling  it,  rendering  it 
subservient,  or  seeking  from  it  arguments  which,  at  most,  cover  up  in  an 
illusory  fashion  the  depreciation  of  the  consciousness,  when  this  is  not  entirely 
obscured.  Meanwhile,  with  reduction  of  the  prophylactic  power  of  logic, 
moral  and  economic  interests  become  enfeebled  ;  the  harmony  between  the 
individual  and  his  social  environment  is  profoundly  disturbed,  because  the 
action  (conduct)  of  the  passionate  man  is  not  a  resultant  of  contrasting 
(propulsive  and  inhibitory)  forces,  but  is  determined  by  one  single  group  of 
emotional  ideas  which  has  taken  possession  of  consciousness,  owing  to  special 
biological  conditions  in  the  development  and  function  of  the  cerebral  system. 
Passion  lowers  the  human  spirit  from  the  elevated  spheres  of  life  to  the 
domain  of  the  primitive  emotions.  Thus  it  happens  that  noble  ambition, 
if  it  becomes  blended  with  poisonous  vanity,  abandons  a  man  to  a  fatuous 
inebriety  which  consumes  a  quantity  of  energy  that  should  be  devoted  to 
logic,  all  the  more  because  the  vain  man  never  possesses  sufficient  energy  to 
realise  his  dreams.  So,  too,  it  comes  about  that  passional  love  becomes  a 
tyrant  dominating  the  intellect,  which  lays  down  its  directive  powers  on  the 
altar  of  love.  Suspicion  and  distrust,  if  they  exceed  a  certain  measure, 
interdict  intellectual  action,  whilst  jealousy  concentrates  cerebral  activity, 
in  a  wasteful  manner,  in  a  mono-idealistic  sphere.  Religion,  when  tempered 
by  intelligent  knowledge  of  life,  is  love,  such  as  is  reflected  in  the  noble  figures 
of  Saint  Francis  of  Assisi,  Saint  Catherine  of  Siena,  Calvin,  Bruno,  and  is  then 
biophylactic ;  when  it  was  perverted  by  fear  of  a  devil  roaming  at  large 
and  ensnaring  souls,  it  gave  rise  to  epidemics  of  obsessions,  of  hysteria,  of 
lycanthropy,  of  flagellation  and  the  terrific  political  criminality  of  those 
times. 

The  moral  sentiment  is  the  highest  expression  of  sentimentality,  and  is 
essentially  constituted  of  ideas  and  experiences  regulated  by  biophylactic 
laws,  and  it  is  the  sentiment  which  has  least  connection  with  the  field  of  the 
organic  phenomena  of  the  emotions. 


EMOTIONS  AND  SENTIMENTS  285 

The  author's  experiments  upon  monkeys  have  shown  that  the  funda- 
mental and  intermediate  emotions  are  preserved  (some  altered)  after  removal 
of  the  frontal  lobes,  whilst  the  higher  sentiments  or  emotions  (as  these  are 
represented,  in  outline,  in  the  monkey)  are  either  absent  or  profoundly  dis- 
turbed, corresponding  with  what  is  observed  to  follow  severe  injury  of  the 
frontal  lobes  in  man.  In  the  case  of  mutilated  monkeys  the  conduct  becomes 
reduced  to  single  reflexes,  dissociated  and  inconsequential,  unfurnished, 
therefore,  with  biophylactic  power,  whilst  at  the  same  time  there  is  a  pre- 
valence of  the  organic  reflexes  of  the  primitive  emotions  (fear,  anger).  In 
normal  monkeys,  on  the  other  hand,  the  conduct  is  prevailingly  more  pro- 
tective ;  it  presents  an  evident  affective  intonation  and  is  more  logical,  being 
based  upon  perceptions,  experiences  and  judgment,  whilst  the  organic  reflexes 
of  the  primitive  emotions  are  much  reduced  in  proportion.  The  most 
striking  evidence  of  this  is  afforded  by  the  social  sentiment,  which  becomes 
abolished  in  monkeys  after  removal  of  the  frontal  lobes.  Sentimentality 
thus  appears  to  be  a  function  more  particularly  of  the  frontal  lobes.  Its 
very  nature,  consisting  as  it  does  of  emotions,  variously  associated  ideas, 
impulses  and  inhibitions,  would  give  us  grounds  for  presupposing  the  exist- 
ence of  organs  that  are  different  from  those  of  the  primitive  emotions.  This 
view  is  supported  by  the  results  of  phylogenetic  and  ontogenetic  investiga- 
tions, dealing  with  the  evolution  of  the  brain,  and  of  the  frontal  lobes  in 
particular,  as  well  as  by  clinical  and  experimental  observations  which  are 
fairly  constant  and  convincing. 


APPENDIX  TO  CHAPTER  IX 

The  Social  Sentiment 

HIGHER  consciousness  is  characterised,  amongst  other  things,  by  the  inter- 
vention of  historical  experience  which  co-operates  with  the  impulses  deter- 
mined by  actual  sensations  and  the  so-called  instincts,  so  as  to  give  rise  to  a 
form  of  conduct  that  is*  the  resultant  of  both  propulsive  and  inhibitive  forces, 
involving  the  element  of  contrast.  The  resultant  represents  the  intuitive 
synthesis  of  energies  directed  towards  the  more  certain  conservation  of  life 
and  the  development  of  the  pleasure  of  existence,  on  a  higher  scale,  and  it 
always  contains  a  utilitarian  element  derived  from  life  in  common,  even  when 
the  community  opposes  inhibitory  elements. 

Many  factors  contribute  in  diverse  manner  and  varying  proportion 
towards  its  development.  Amongst  these  the  chief  are  : 

1.  The  development  of  the  posterior,  sensory  mantle,  which  includes  all 
that  part  of  cerebral  cortex  extending  from  the  fissure  of  Rolando  to  the 
occipital  pole,  and  from  the  interhemispheric  surface  to  the  inferior  aspect 
of  the  cerebral  hemisphere.    From  this  development  is  derived  the  pro- 
gressive perfecting  of  the  perceptive  and  emotive  capacity,  and  hence  the 
progressive  process  of  assimilation  of  the  thoughts,  emotions  and  conduct 
of  the  environment,  and  also  of  the  language  of  nature,  with  the  individual 
consciousness. 

2.  The  development  of  the  mnemonic  activity  attached  to  individual 
and  collective   experience,  this  impressing  a   certain  orientation  and  di- 
rective upon  conduct,  which,  to  some  extent,  reflects  the  habits  of  life  of 
the  community,  in  accordance  with  the  law  of  imitation  and  hedonistic 
adaptation   (conservation  and  development),  and  in  part  manifests  the 
creative  power  of  the  human  brain,  based  upon  association  (phantasy, 
imagination) . 

3.  The  evolution  of  the  social  sentiments,  which  are  intellectual- emotional 
syntheses  of  an  experiential  and  historical  order,  and  may  be  represented 
as  the  resonance,  in  one's  own  consciousness,  of  the  emotions  of  other  beings 
with  whom  one  lives  (reflex  reproduction),  along  with  the  necessary  observ- 
ance of  all  social  obligations  imposed  by  the  beliefs,  sentiments,  and  needs 
of  each  individual  in  relation  to  the  environment  and  to  the  customs  of  the 
social  group,*  customs  which  aim  at  defence  from  hurt  and  the  promotion 
of  well-being. 

*  In  this  connection,  one  may  again  refer  to  facts  that  are  constantly  observed 
in  monkeys  which  have  suffered  mutilation  of  the  frontal  lobes — e.g.  the  complete 
indifference  they  manifest  not  only  towards  those  who  have  been  in  the  habit  of 
tending  them,  and  for  whom  they  formerly  showed  affection,  but  also  towards  their 

286 


APPENDIX  TO  CHAPTER  IX  287 

The  mnemonic  process  becomes  daily  richer  in  experiences  and  wealthier 
in  content  and  this  accelerates  and  intensifies  the  directive  power  over 
conduct,  because  of  the  greater  coefficient  furnished  by  the  memory  of  past 
experience  derived  from  life  in  common  (reciprocal  defence  and  protection, 
greater  efficacy  of  life  in  common  in  the  struggle  for  existence,  beliefs,  customs, 
etc.).  The  impulse  given  to  this  process  by  the  accelerating  power  of  writing 
is  enormous  as  compared  with  the  influence  of  traditions  transmitted  by  word 
of  mouth  or  in  the  form  of  customs  (the  enormous  progress  of  mankind  is 
due  to  the  development  of  the  printing  press). 

The  emotions  and  thoughts  of  the  social  environment,  when  assimilated 
by  an  individual,  take  a  prominent  part  in  the  structure  of  his  consciousness 
and  in  the  determinism  of  his  conduct,  which  is  the  resultant  of  impulses 
provoked  by  ends  in  view,  to  the  attainment  of  which  there  co-operate  the 
individual  and  personal  desires,  sentiments  and  aspirations,  tempered  by  the 
desires,  sentiments  and  aspirations  of  others. 

We  cannot  imagine  a  state  of  consciousness  from,  which  the  conduct  of 
every  man  is  derived,  apart  from  social  relations.  These  give  us  the  outline 
of  the  moral  sentiment. 

The  social  sentiment,  or  what  may  be  called  sociality,  has  been  going  on 
developing  by  degrees  and  in  man  has  extended  its  domain  from  the  cavern 
to  the  tribe,  to  groups  of  habitations,  to  communities,  to  regions,  to  the 
nation,  to  the  race,  to  internationalism,  in  regular,  inevitable  fashion.  The 
interhuman  entente,  which  marks  one  of  the  aspects  of  human  progress, 
though  interrupted  by  periods  of  unheard-of  ferocity  or  hidden  by  egoism 
(to-day  we  see  it  arrested  at  the  more  advanced  stage  of  one  race  versus 
other  races),  uprises  like  a  dawning  sun,  smiling  upon  many  nations 
(internationalism),  and  will  reach  its  zenith  in  the  assured  existence  of  the 
more  evolved  human  groups.  There  is  no  longer  any  room  for  doubt  on 
this  point.* 

Sociality  has  a  long  and  slow  evolution.  We  find  it  in  the  most  varied 
forms  in  insects,  birds  and  mammals.  In  middle-grade  and  even  lower- grade 
monkeys,  such  as  cercopithecus  and  cibus,  it  assumes  rather  human-like 
features.  These  may  no  doubt  be  rudimentary  but  they  nevertheless  present 
such  manifestations  as  leave  no  doubt  about  its  actual  existence.  Sociality 
is  an  integral  element  of  mind  and  disappears  entirely,  so  far  at  least  as  its 
symptomatic  manifestations  are  concerned,  after  mutilation  of  the  frontal 
lobes,  and  in  almost  all  forms  of  mental  disease  in  the  human  subject. 

fellow-creatures,  whose  life  in  common  is  characterised  by  undoubted  manifestations 
of  the  social  sentiment. 

*  The  author  had  already  written  an  article  on  this  subject  (Ferrari's  Eivista  di 
Psicologia  Applicata,  1917),  when  the  notion  regarding  the  League  of  Nations,  so 
strongly  supported  by  President  Wilson,  began  to  take  shape.  Wilson,  who  seems 
not  to  have  had  a  full  conception  of  the  diplomatic  prejudices  of  old  Europe,  has 
shown  a  marked  incoherence,  because,  although  he  has  given  proof  of  a  high  degree 
of  sociality,  as  this  sentiment  is  conceived  by  psychologists  and  naturalistic  sociolo- 
gists, he  has  failed  to  meet  the  practical  difficulties,  and  to  free  himself  from  the  old 
formula1  of  International  politics. 


288  THE  MECHANISM  OF  THE  BRAIN 

Reduction  or  suppression  of  sociality  is  a  feature  which  the  writer  has 
constantly  observed  in  monkeys  which  have  suffered  mutilation  of  the  frontal 
lobes  and  also  in  imbeciles  whom  he  has  had  under  observation  for  years, 
No  one  who  has  had  experience  of  the  mental  make-up  of  phrenasthenics, 
especially  in  cases  of  profound  mental  deficiency,  can  have  failed  to  notice 
the  isolation  in  which  these  afflicted  subjects  pass  their  existence.  In  the 
less  degraded,  one  may  certainly  observe  signs  of  attachment  to  some  person 
or  other,  but  this  is  for  the  immediate  advantage  to  be  derived  therefrom, 
just  as  in  the  case  of  monkeys,  dogs,  and  even  birds,  which  exhibit  pleasure 
when  approached  by  persons  who  give  them  things  to  eat  or  otherwise  show 
them  attention.  Sometimes  this  semblance  of  attachment  to  these  persons 
is  the  corrective  of  fear,  which  predominates  over  all  other  emotions,  in 
imbeciles  and  many  inferior  beings,  and  it  promotes  a  sense  of  protection 
on  the  part  of  persons  who  are  in  the  habit  of  taking  care  of  these  weaklings. 
Sometimes  what  we  get  is  a  mere  imitation  of  attitudes,  simulating  an  affec- 
tion or  sentiment  which  does  not  actually  exist,  as  in  the  case  of  shame  or 
religion,  sentiments  which  find  no  place  in  the  spirit  of  imbeciles.  These 
beings  live  a  life  apart  from  their  fellows  and  from  other  men.  Their  minds 
take  no  share  in  the  griefs  or  joys  of  those  amongst  whom  they  pass  their 
existence.  If  a  piece  of  bad  fortune  overtake  the  family,  the  imbecile 
remains  indifferent.  If  he  weep,  he  merely  imitates  ;  if  he  laugh,  it  is  only 
a  mechanical  reflex,  a  purely  individual  affair,  void  of  any  participation  in 
the  joy  of  the  community.  Egoistic  and  egocentric  imbeciles  are  incapable 
of  acts  of  generosity,  and  this  is  true  even  of  the  less  degenerate.  If,  at 
school,  they  exchange  some  words  with  other  scholars  or  give  any  sign  of 
approach,  it  is  nothing  more  than  an  imitative  mechanism,  without  participa- 
tion of  that  sentiment  of  joy  that  springs  from  companionship.  If  they  beat 
their  chests,  at  home  or  in  church,  it  is  not  from  religious  sentiment ;  they 
are  either  imitating  at  the  moment,  or  remembering  what  they  have  seen ; 
their  souls  remain  unthrilled  by  true  sentiment.1 

In  monkeys,  we  have  observed  a  number  of  manifestations  which  present, 
in  a  rudimentary  or  embryonic  fashion,  the  features  of  human  sociality. 
The  histories  of  those  animals,  which  the  author  had  under  observation  for  a 
long  time,  both  before  and  after  mutilation  of  the  frontal  lobes,  have  revealed 
facts  of  some  considerable  importance  to  anatomical  psychology,  to  the 
furtherance  of  which  these  researches  were  directed.  A  cercopithecus, 
e.g.,  one  day  met  in  the  garden  a  black  dog  which  had  had  one  of  its  frontal 
lobes  removed.  At  first  the  monkey  was  afraid  and  took  refuge  in  a  tree. 
Several  times  it  came  down  from  its  perch  and  cautiously  approached  the 
dog,  but  each  time,  as  the  dog  came  towards  it,  it  made  off  again  and  ran  for 
the  tree.  After  many  repetitions  of  this  scene  the  monkey  seemed  to  become 
persuaded  that  the  dog  was  good-natured  and  so  it  cautiously  drew  near, 
retreating  and  advancing  from  time  to  time  until  it  finally  came  near  to  the 
dog  and,  stretching  out  a  hand,  caressed  it.  Encouraged  by  this  first  success, 
it  stood  in  front  of  the  dog  and  with  its  other  hand  patted  the  other  cheek, 
1  Maschka.  L.  Bianchi.  Trait,  di  Psich.  2nd  edit.  1915. 


APPENDIX  TO  CHAPTER  IX     "  289 

then  stroked  the  head  and  passed  its  hand  under  the  lower  jaw.  Coming 
still  closer,  it  touched  the  dog  all  over  with  an  air  of  solicitude  and  curiosity, 
as  though  wanting  to  make  friends. 

In  order  to  keep  this  sympathetic  cercopithecus  under  closer  observation, 
the  author  decided  to  take  it  home.  Signora  Bianchi  carried  a  small  satchel 
suspended  at  the  waist  and  in  it  were  chestnuts,  roasted  and  shelled,  which 
she  gave  to  the  monkey.  Soon  it  came  about  that,  whenever  she  passed  by, 
the  monkey  would  jump  up  on  her,  paw  her,  and  take  hold  of  the  satchel, 
which  it  soon  learned  to  open.  It  was  very  jealous.  One  day  Signora 
Bianchi  entered  the  room,  where  the  monkey  was,  carrying  a  friend's  baby 
in  her  arms.  It  was  fortunate  that  the  monkey  was  chained,  because  as 
soon  as  it  saw  her  with  the  baby  in  her  arms  it  became  wild  and  excited, 
such  as  it  had  never  been  before.  It  ground  its  teeth  and  made  attempts 
to  get  hold  of  the  infant  and  only  quietened  down  when  Signora  Bianchi 
went  away  with  the  child  and  came  back  alone. 

From  the  facts  mentioned  in  the  record  of  the  experiments  described  in 
Chapter  V.  (apart  from  the  fairly  abundant  literature  dealing  with  the  life 
and  habits  of  monkeys — Gamier,  Thorndike,  Brehm)  one  can  draw  con- 
clusions as  to  the  degree  of  evolution  of  the  emotions  which,  in  monkeys, 
are  seen  to  be  taking  on  the  character  of  sentiments,  .even  granted  these 
have  mainly  an  alimentary  or  sexual  content,  sentiments,  however,  which 
pass  beyond  the  limits  of  immediate  interest  and  extend  into  the  fields  of 
friendship,  gratitude  and  protection,  which  are  the  fundamental  elements  of 
sociality. 

In  every  case  of  mutilation  of  the  frontal  lobes  in  monkeys,  what 
was  found  to  be  suppressed  was,  without  exception,  that  sentimentality 
or  feeling  for  others  that  we  designate  as  sociality.  A  similar  condition 
exists  in  human  beings  who  have  suffered  severe  injury  to  both  frontal 
lobes  and  in  those  whose  frontal  brains  are  imperfectly  developed.  The 
majority  of  the  insane  exhibit  the  same  feature.  Sociality  is  thus  a  psychic 
manifestation  which  comes  with  evolution.  It  varies  in  different  indi- 
viduals and  races  and  becomes  suppressed  by  mental  disease  and  severe 
frontal  lesions. 

Gr.  Pellacani 1  declares  that  social  conduct  in  animals  is  instinctive.  This 
may  be  granted  if  we  take  instinct  to  mean  the  social  attitude  emanating 
from  a  psycho-anatomical  structure  in  course  of  evolution.  No  one  can  fail 
to  notice  the  gradual  passage  of  the  so-called  instinct  of  lower  animals  to 
the  sociality  of  monkeys.  From  the  gregarious  instinct  of  ants  and  bees, 
to  that  of  birds  (pigeons,  swallows,  cranes  and  a  number  of  other  birds  of 
passage) ;  from  the  latter  to  the  gregarious  instinct  of  the  beaver  and  some 
of  the  higher  mammals,  especially  the  elephant,  and  finally  to  the  gregarious 
instinct  of  the  monkey,  we  have  a  graduated  scale  in  which,  step  by  step, 
new  intellectual  and  sentimental  elements  make  their  appearance,  and  with 
the  intervention  of  these  the  features  of  the  so-called  instinct  become  lost. 

1  Pellacani.     /  problemi  delta  istintivitct,  nella  condotta  umana.     Bologna,  1915. 
T 


290.  THE  MECHANISM  OF  THE  BKAIN 

One  of  the  characteristics  of  instinct*  is  its  immutability,  and  if  we  subject 
members  of  any  of  the  more  evolved  groups  in  the  above-mentioned  zoological 
scale  to  examination  we  find  that  the  supposed  instinct  does  not  remain  at 
the  same  level  but  exhibits  individual  variations  and  mutations  which  are 
determined  by  adaptation  to  a  more  assured  (evolved)  level  of  existence. 
The  adaptation  is  brought  about  by  a  more  perfect  perception  of  the  environ- 
ment, and  a  consequent  enlightenment  of  consciousness.  This  progression 
(and  complication)  of  the  primitive  instinct  is  based  upon  associative  memory 
and  is  apparently  incited  by  the  struggle  for  existence,  bound  up  with  the 
rising  hedonism,  which  reaches  its  highest  level  in  man. 

Many  writers  make  reference  to  conflict  between  the  individual  and  the 
social  environment.  Yet,  in  the  more  advanced  states  of  society,  it  is 
difficult  to  detect  conflict  between  the  individual  and  the  social  group,  the 
reason  evidently  being  that  the  group  gives  rise  to  a  hedonistic  influence 
which  conforms  the  lif e  of  the  individual  to  that  of  the  environment,  even  from 
infancy.  In  the  words  of  James  :  "  With  the  child,  lif  e  is  all  play  and  fairy 
tales  and  learning  the  external  properties  of  things ;  with  the  youth  it  is 
bodily  exercise  of  a  more  systematic  sort,  novels  of  the  real  world,  boon- 
fellowship,  and  song,  friendship  and  love,"  and  so  the  social  spirit  of  the 
young  person  is  formed.  Other  factors  have  to  be  taken  into  account : 
the  suckling,  the  smiles,  caresses  and  kisses  of  the  mother  and  other  members 
of  the  family ;  the  solicitude  manifested  with  regard  to  the  satisfaction  of 
the  vital  requirements ;  the  trouble  taken  in  promoting  the  development 
of  the  aesthetic  sense  of  the  proper  self,  which  begins  to  spring  up  with  the 
tidy  dress,  the  curled  hair,  the  sensual  caressing  and  the  praises  bestowed 
upon  the  beauty  and  intelligence  of  the  child ;  the  toys,  and  the  singing  to 
sleep  and  so  forth.  Painful  experience  also  plays  its  part,  counterbalanced 
by  the  experience  of  comfort  and  protection  that  is  derived  from  the  family 
and,  later  on,  from  society. 

In  the  contrast  between  experiences  of  a  pleasant  -nature  and  those 
consequent  upon  denied  satisfaction  of  desires,  expectations  and  impulses ; 
in  the  sum  total  of  satisfactions  and  inhibitions  experienced,  even  if  the  latter 
be  the  effect  of  coercions  (education),  hedonistic  sensations  always  prevail, 
at  least  in  natures  normally  conformed,  and  these,  with  the  help  of  new 
sensory  grafts  and  associative  mental  formations,  give  root  to  the  gregarious 
sensations.  Contrast  and  conflict  belong  to  inferior  natures,  or  depend  upon 
violent  methods  of  coercion,  not  calculated  to  attemper  the  nascent  hedonism 
to  stern  reality,  or,  again,  are  due  to  misery  which  robs  the  environment 
of  every  happiness. 

Under  normal  conditions  in  modern  civilised  life,  progressive  adaptation 
to  the  social  environment  is  apparent  from  infancy.  From  the  environment 


*  A  discussion  of  instinct  does  not  fall  within  the  scope  of  this  work,  but  the 
writer  would  maintain  the  term  instinct  in  the  nomenclature  provided  only  it  have 
a  very  different  signification,  such  as  that  of  aptitude,   dependent  upon  special, 
inherited,  anatomical  structure.     We  may  have  structural  evolution,  but  with  tha 
we  get  variations  in  attitude. 


e 

• 

1 


APPENDIX  TO  CHAPTER  IX  291 

there  is  an  inflow  of  integrative  currents  whilst  from  the  infant  there  is  a 
reflow  of  actions  which  are  constructive  of  the  nascent  personality,  these 
returning  as  an  unconscious  homage  to  the  social  consciousness.  The  great 
joys  in  life  spring  from  the  social  relations,  whatever  be  their  nature,  more 
especially  when  man  is  adapted  to  his  environment,  and  still  more  when  his 
action  is  beneficent.  It  is  only  weak  and  sickly  natures  that  adapt  them- 
selves with  difficulty  and  have  a  painful  consciousness  of  the  flow  of  the 
human  senses — painful  because  such  individuals  are  incapable  of  a  hedon- 
istic assimilation  of  the  social  currents  and  of  reaction  which  permits  the 
individual  ego  to  find  its  level  in  the  environmental  harmony. 

With  the  development  of  the  human  psyche  (psychogenesis)  there  dis- 
appears what,  by  way  of  euphemism,  has  been  termed  social  instinct.  This 
occurs  not  by  suppression  of  the  phylogenetic  content,  but  by  a  slow  trans- 
formation, in  the  structure  of  the  personality,  of  all  the  more  important  and 
formal  elements  of  antecedent  life,  and  by  assimilation  of  the  impulses  of 
the  actual  social  environment.  The  innate  impulses  and  tendencies  which 
make  man  appear,  to  some,  to  be  an  instinctive  being,  are  only  complicate 
reflexes  of  innumerable  stimuli  coming  from  the  environment  and  assimilated 
with  the  consciousness. 

Waxweiler,1  after  mentioning  that  the  question  of  the  instincts  has  now 
been  submitted  to  experimental  methods  in  the  laboratory,  remarks  that 
he  foresees  the  day  when  the  word  instinct  will  disappear  from  scientific 
terminology. 

Liberty  is  not  to  be  regarded  as  an  invariable  quality  belonging  to  the 
individual  but  as  a  social  compromise,  according  with  the  consciousness  of 
all.  It  is,  in  a  biological  sense,  a  reflex  of  the  social  content,  a  trans- 
formation of  receptive  elements  and  fusion  of  these  with  the  experiential 
elements  of  the  individual  life  and  of  the  gregarious  life  of  the  social  group, 
resolved  into  conduct.  The  mechanism  becomes  increasingly  complicated 
through  the  gradual  dignification  of  the  reflex  and  variation  in  the  inherited 
substratum  (family  and  ethnic)  which  manifests  itself  in  a  biological  pre- 
disposition to  feel  the  environment  in  a  different  way  and  to  react  in  the 
most  varied  manner. 

Language  assists  towards  a  more  rapid  development  of  sociality.  To 
the  sensory  experience  of  the  individual  there  is  added,  by  degrees,  that  of 
the  emotions  and  cognitions  of  other  men,  translated  into  phonetic  articulate 
symbols,  which  afford  a  more  perfect  acquaintance  with  the  states  of  mind 
of  all  the  components  of  a  social  group.  It  participates  in  the  emotions  of  the 
environment  in  proportion  to  the  greater  intensity  of  the  interhuman  impulses 
afforded  by  the  increased  number  of  paths  and  means  of  communication 
with  the  states  of  mind  of  other  fellow-beings  amongst  whom  the  individual 
is  spending  his  existence.  The  intellectual- emotional  elements  of  the 
environment  constitute  a  very  rich  material  for  the  construction  of  human 

1  Waxweiler.  "  Sur  la  modification  des  instincts  sociaux."  Soc.  <T  Anthro- 
pologie  de  Bruxelles.  1907. 


292  THE  MECHANISM  OF  THE  BRAIN 

mentality.  The  latter  is  an  activity  that  is  changeable  in  content,  in  methods, 
in  intensity  and  results,  and  has  nothing  in  common  with  instinct.  In 
opposition  to  the  notion  expressed  by  Baldwin1  one  may  put  forward  the 
conception  that  there  is  nothing  innate  except  the  biological  predisposition 
to  react  favourably  in  a  hedonigenous  environment.  As,  however,  the 
reaction  is  variable,  the  reactive  variability,  even  when  set  in  motion  by 
internal  impulses,  has  not  the  character  of  instinct.  It  is,  above  all,  the 
environment,  with  its  numerous  and  varied  currents  of  sentiments,  with  all 
its  compulsive  forces,  its  habits,  its  labour,  its  joys  and  its  griefs,  that 
nourishes  the  social  sense  and  social  habits,  although  the  methods  involved 
are  very  dissimilar — subjection  and  dependence,  compulsion,  imitation,  sug- 
gestion, faith,  and  sympathy,  which  itself  is  rather  a  complex  psychological 
factor  capable  of  determining  different  forms  of  adaptation. 

Boccardo 2  has  expressed  the  view  that  "  goods  "  are  the  connective  tissue 
of  the  social  body.  No  doubt  the  economical  factor  possesses  a  great  power 
of  cohesion  amongst  the  social  components,  but  many  other  factors  have 
to  be  taken  into  account. 

Some  of  these  forces,  such  as  subjection  and  compulsion,  act  more 
strongly  in  the  case  of  infants  and  feeble  persons,  whilst  imitation,  sug- 
gestion, sympathy,  and  interest,  even  in  the  guise  of  "  goods,"  are  the  great 
forces  which  act  upon  the  human  mass  and  on  its  diverse  and  varied 
groups. 

In  the  more  highly  evolved  mammals,  such  as  monkeys,  we  can  detect 
a  very  rudimentary  degree  of  all  these  forces  acting  upon  their  sociality,  on 
a  hedonistic  basis.  Thus,  we  get  protection  in  the  case  of  the  stronger, 
subjection  in  the  case  of  the  weaker ;  also  the  greater  security  which  comes 
of  number,  the  despair  which  arises  from  solitude  in  new  surroundings 
(whence  the  comfort  afforded  by  hearing  the  voices  of  distant  companions), 
and  sympathy.  All  these  are  based  upon  fundamental  emotions  and,  along 
with  a  certain  capital  of  mnemonic  representations  with  a  prevailingly  pro- 
tective, alimentary  or  sexual  content  and  a  significant  degree  of  perceptive 
penetration,  determine  a  behaviour  which,  though  it  still  obeys,  in  the  main, 
the  vital  laws  of  attraction  and  repulsion,  reveals  in  the  variety  of  attitudes 
a  certain  level  of  consciousness  which  affords  a  measure  and  means  whereby 
we  can  estimate  the  effects  of  removal  of  the  frontal  lobes.  In  all  these 
vital  and  reactive  manifestations  we  find  neither  an  invariable  programme 
nor  distinctly  fixed  rules,  but  momentary  variations  corresponding  with  a 
wider  perception  of  the  environment  and  more  complex  modes  of  adaptation 
thereto. 

The  marvellous  mental  and  social  development  of  mankind  in  the  later 
millenniums,  as  compared  with  the  slow  and  laborious  evolution  of  the  palaeo- 
lithic and  neohthic  periods,  is  due,  as  already  mentioned,  to  spoken  language 

1  Baldwin.     Mental  Development  in  the  Child  and  in  the  Race.     New  York,  1906. 

2  Boccardo.      Raccolta   delle    piii    pregiate   opere   moderne   di    economia    politica. 
Vol.  vii.     1871. 


APPENDIX  TO  OHAPTEK  IX  293 

in  the  first  instance  and  subsequently  to  writing.  Speech  is  the  ocean  in 
which  all  forms  of  consciousness  become  immersed,  throwing  off  the  last 
remnants  of  the  instinctive  preformations  and  emerging  again  to  attain  the 
mobility  of  human  consciousness  as  we  find  it  in  the  infinite  variety  of  in- 
dividuals and  groups.  The  prelogic  mentality  to  which  Levy  Bruhle1  refers 
probably  corresponds  to  the  first  stages  of  the  development  of  language, 
inasmuch  as  the  logical  process  involved  in  lengthy  reasoning  is  only 
possible  with  the  help  of  language. 

Writing,  on  the  other  hand,  permits  an  enormous  accumulation  of 
material,  consisting  of  human  thought  and  experience,  in  the  archives  of  the 
universal  intellect,  and  from  these  are  culled  the  norms  for  new  social  sen- 
sations, norms  which  correspond  more  fully  and  adequately  with  the  new 
attitudes  of  life  in  common,  in  accordance  with  the  pressing  requirements 
of  the  individual  and  the  social  hedonistic  consciousness.  Hence  comes 
about  the  marvellous  activity  displayed  by  mankind  in  the  economic  field, 
which  daily  becomes  more  and  more  controlled  by  scientific  truth,  for  the  in- 
tellect is  ever  striving  anxiously  after  truth,  in  an  endeavour  to  mould  and 
direct  human  activity  which,  in  turn,  is  becoming  ever  more  disciplined 
and  regulated  by  social  sanction.  With  advance  in  civilisation  man  makes 
fuller  use  of  intellect,  whilst  the  intercourse  and  interchange  between  men 
is  attended  with  more  mutual  advantage.  Primitive  societies,  composed  of 
poorly  differentiated  men,  permit  but  a  slow  growth  of  intellect  and  the  use 
they  make  of  what  intellect  they  do  possess  is  much  less. 

If  we  cannot  agree  with  the  notion  that  there  exists  a  social  instinct  it  is 
because  the  attitudes  of  each  individual  in  his  environment  vary  under  the 
influence  of  an  enormous  number  of  stimuli  and  circumstances.  They  vary 
in  accordance  with  the  infinite  variety  of  perceptions  in  the  environment  in 
which  he  is  developed,  and  also  according  to  individual  and  collective  experi- 
ence. Again,  they  vary  with  variations  in  the  individual  capacity  for  the 
reception  of  stimuli — i.e.  with  the  degree  of  excitability.  There  is,  however, 
something  in  all  this  which  is  stable,  but  it  is  not  instinct  nor  is  it  characterised 
by  a  fixed  mode  of  reacting  :  it  is  the  predisposition  to  feel  the  social  influx, 
which  in  turn  determines  conduct. 

In  this  respect  one  can  agree  with  Baldwin  when  he  asserts  that  we 
inherit  the  physical  variations  of  the  cerebral  plasticity,  for  this  conforms 
to  experience  of  the  environment. 

It  matters  little  whether  the  human  aggregates  which  constitute  social 
groups  are  to  be  considered  as  organisms  governed  by  laws  pertaining  to  the 
life  of  individuals  (biological),  as  maintained  by  upholders  of  the  organic 
doctrine,  Spencer,  Worms,  Schafer,  Novikow,  and  others,  or  whether  they  are 
governed  by  intuitions  and  economic  determinism  as  maintained  by  Marx, 
Loria,  De  Molinari  and  others.  In  each  case  the  guiding  principle  is  the 
unconscious  law  of  adaptation  and  natural  selection  aided  by  the  accelerated 
evolutionary  movement  of  the  psychic  activities  caused  by  modifications 

1  Levy  Bruhle.  Sur  la  fonction  mentale  dans  les  societes  injerieures.  Paris, 
1910. 


294  THE  MECHANISM  OF  THE  BRAIN 

determined  by  the  group.  Comte,  influenced  by  the  notions  of  Saint-Simon, 
expressed  a  belief  in  the  existence  of  one  single  law,  in  accordance  with  which 
human  societies  would  develop.  This  conception  was  further  developed  by 
Spencer,  who  arrived  at  the  conclusion  that  human  societies  are  particular 
forms  of  existence  shaped  by  the  same  laws  as  those  which  preside  over  the 
evolution  of  the  universe. 

There  is  a  certain  parallelism  between  the  evolutionary  movement  of 
the  mind  to  which  reference  has  been  made,  and  the  total  sum  of  stimuli, 
inasmuch  as  every  acquisition  and  every  variation,  in  the  way  of  more 
advantageous  adaptation  on  the  part  of  each  individual,  becomes  the 
patrimony  of  the  group ;  division  of  labour  which  gives  rise  to  mental 
and  operative  differentiation  is  another  factor  which  must  here  be  taken 
into  account. 

Tarde,1  indeed,  maintains  that  all  social  facts  are  due  to  individual 
inventions  propagated  by  imitation.  To  him  invention  is  a  supreme  acci- 
dent in  which  foresight  plays  no  part,  and  it  gives  rise  to  that  imitative 
well-being  which  is  a  constant  feature  of  every  social  fact. 

Economic  organisation  is  the  effect  of  a  biological  situation  and  it  may 
promote  evolutionary  economic  advances,  which  are  regulated  by  a  number 
of  individual  and  collective  psychic  factors,  mainly  the  following : — -the 
different  evolutionary  capacity  of  different  individuals  belonging  to  one 
and  the  same  group  in  the  same  environment ;  secondary  variations  of  the 
environment  and  differentiation  of  labour,  whence  arise  biological  and 
psychological  variations  ;  differences  in  the  mode  of  perceiving  and  feeling  ; 
differences  in  the  amount  of  mental  capital  available  and  in  the  aptitude 
for  utilising  it  and  for  acting. 

If  it  is  true  that  functional  variations  correspond  with  structural  modi- 
fications and  that  morphogeny  corresponds  with  psychogeny,  we  will  take 
into  account  the  fact  that  along  with  the  general  features,  common  to  the 
social  group,  we  meet  with  individual  differences.  The  former  are  summed 
up  in  customs  and  creeds,  the  latter  vary  considerably  because  they  depend 
upon  a  great  variety  of  factors,  amongst  which  are  to  be  enumerated  the 
following  : — the  complex  and  varied  mental  structure  of  different  individuals 
and  their  genitors,  their  predominating  emotions,  their  morphogeny — which 
may  be  altered  under  the  influence  and  impulses  of  psychic  states — the 
numerous  circumstances  under  which  fecundation  and  gestation  take  place, 
intoxications  of  the  nemasperm  and  the  ovule  (a  product  of  civilisation), 
crossed  matings,  and  differences  in  occupation,  which  in  turn  determine 
new  morphological  variations  and  new  functional  developments,  and  open 
up  new  fields  of  ideas  and  aspirations. 

The  social  phenomenon  is  one  of  great  complexity  and  almost  all  doctrines 
relating  thereto  contain  some  germs  of  truth.  The  structure  of  the  family, 
religions,  creeds,  the  organisations  of  labour,  differentiation  of  which  creates 
new  social  bonds,  are  amongst  the  more  important  factors.  Labour  organisa- 
tions to-day  are  no  longer  the  simple  and  elementary  forms  of  social  existence 
1  Tarde.  Les  Lois  Sociales.  1898. 


APPENDIX  TO  CHAPTER  IX  295 

mentioned  by  Le  Play,1  but  are  complex  organisations  whose  groups  are 
bound  together  by  the  perfection  of  the  product  (the  finished  article),  by 
economic  interests,  by  sanitary  interests,  etc. 

Apart  from  all  this,  however,  there  is  no  doubt  as  to  the  existence  of  the 
social  sentiment.  It  is  seen  in  love  and  hatred,  faith  and  diffidence,  co- 
operation and  individualism,  security  and  dread,  help  and  treachery,  exalta- 
tion and  humiliation,  victory  and  defeat,  pride  and  humility — in  short,  in 
moral  pleasure  and  moral  pain,  in  every  variety  and  every  degree,  as  summed 
up  in  the  fundamental  law  of  contrast  which  regulates  life,  with  its  victory 
of  hedonism  over  negativism.  It  is  a  product  of  collectivism,  in  the  social 
sense,  of  intimacy,  of  co-operation  and  mutual  protection,  and,  at  the  same 
time,  of  the  consciousness  of  personal  energy  and  personal  contribution  to  the 
prosperity  of  the  environment.  In  the  sentiment  of  co-operation  one  can 
behold  heterogeneity  co-ordinated  with  the  homogeneity  of  the  social  group. 
The  social  sentiment  emanates  from  a  combination  of  sentiments  and  ideas 
(the  intellectual  elements  of  the  social  sentiment),  the  latter  more  than  the 
former,  which  together  represent  a  complicate  function,  which  in  turn  has 
determined  an  enlargement  of  the  cerebrum  and  a  differentiation  of  its  parts, 
under  the  pressing  stimulus  of  the  hedonistic  victories  to  which  life  inevitably 
aspires. 

Language  and  sociality  proceed  pan  passu.  All  emotions  contain  an 
expressive  element.  This  gradually  becomes  transformed  from  the  palpita- 
tion, the  trembling  and  pallor  of  fear  to  the  cry,  the  voice,  the  look,  the  caress, 
the  first  lispings,  and  to  speech,  in  the  more  evolved  emotions.  We  can  detect 
this  progressive  transmutation  in  all  the  phases  of  evolution  in  the  growing 
infant.  To  the  primitive  emotions  of  pleasure  and  of  pain,  with  which 
organic  changes  are  closely  related,  as  already  set  forth,  there  are  added  the 
complex  pleasures  and  pains  that  arise  with  inter-human  relations,  and  these 
find  their  expressive  paths  and  fields  in  speech  and  conduct.  Patriotism,  the 
spirit  of  self-denial,  the  sacrifice  of  life  as  a  burnt  offering  upon  the  altar  of 
the  Motherland,  love  and  religion  in  the  purest  expressions  of  art  and  of 
language,  and  in  abstinence  from  organic  pleasures,  are  nothing  else  than  the 
sublimation  of  the  primitive  emotions. 

With  the  development  of  their  relations  and  means  of  communications, 
all  societies  which  have  attained  a  very  high  development  tend  to  become 
like  one  another.  Their  legislation,  civil  rights  and  provisions,  their  scholastic 
institutions,  the  products  of  their  lands  and  workshops,  show  a  constantly 
increasing  similarity.  Democratic  politics  is  daily  extending  and  gaining 
ground ;  the  humanitarian  sentiment  is  insinuating  itself  into  the  popular 
consciousness,  though  still  rather  weak  to  combat  successfully  the  old 
tendencies  and  old  ideas  of  conquest  and  dominion  that  pertain  to  some  races. 
The  struggle  for  life  and  fortune  between  the  social  groups  has  assumed  a 
different  character :  it  is  a  struggle  based  on  intellect,  on  industry  and  on 
courage. 

1  Le  Play.     Les  Ouvriers  Europeens.     2nd  edit.  1855. 


296  THE  MECHANISM  OF  THE  BRAIN 

Differences  between  social  groups  dependent  upon  physical  environment 
or  upon  the  original  nucleus  of  each  race  or  upon  social  experiences  or  upon 
the  organisation  and  differentiation  of  labour,  as  well  as  upon  the  political 
order  of  things,  are  becoming  less  noticeable.  In  proportion  as  civilisation 
is  making  rapid  strides  in  the  sciences,  which  every  day  unearth  new  sources 
of  natural  energies,  subserving  these  with  astounding  rapidity  to  the  in- 
dividual and  collective  life,  mysticism  is  dying  out,  and  there  lies  before  us  a 
period,  probably  a  long  period,  of  indifference,  in  relation  to  spiritual  habits 
and  popular  beliefs.  Meanwhile  there  springs  up,  quivering  and  trembling, 
the  sentiment  of  human  liberty,  individual  and  collective,  giving  more  allur- 
ing promise  in  the  free  and  unrestricted  rivalry  between  all  civilised  peoples 
as  they  vie  with  one  another,  with  the  products  of  their  work,  in  the  race  for 
fortune.  Crusades  for  religions,  which  no  doubt  represented  an  important 
stage  in  the  progress  of  civilisation,  are  now  being  followed  by  crusades  in 
the  interest  of  health  and  well-being  and  crusades  against  the  domination 
and  conquest-making  tendencies  of  any  race  which  acts  the  part  of  a  con- 
spirator, concealing  its  treachery  and  lust  for  dominion  under  the  plea  of 
freedom  to  develop  the  activities  and  life  of  its  people  or  of  regard  for  its 
possessions.  Interhuman  contacts  and  exchanges  tend  towards  uniformity 
in  life  and  customs,  and  to  a  closer  understanding,  which  resolves  itself  into 
the  sentiment  of  human  solidarity. 

Whilst  the  sentiment  of  humanity  and  solidarity  is  always  adding  new 
constituent  elements  to  consciousness,  it  observes  the  fundamental  law  of 
hedonism  which  assures  new  sources  of  pleasure  and  of  power  in  the  struggle 
for  existence,  as  well  as  a  larger  and  more  reliable  measure  of  protection  to 
the  individual  and  collective  life. 

After  long  and  bloody  struggles,  the  evolution  of  the  sentiment  of  humanity 
and  liberty  has  suppressed  the  tyranny  of  caste,  kings  and  religions.  Man- 
kind is  progressing  towards  a  state  of  equilibrium  in  which  there  will  be  equal 
freedom  for  all  in  applying  the  personal  energies  to  work  and  progress, 
allowance  always  being  made  for  differences  in  intellectual  and  physical 
strength  which  are  unavoidable  individual  prerogatives,  along  with  their 
legitimate  effects  upon  economic  conditions,  for  these  are  inevitable  and 
irreducible  consequences  of  human  differences,  as  regards  both  individuals 
and  groups.  It  is  from  these  that  the  new  religion  of  culture  and  health 
takes  its  origin. 

The  evolutionary  process  in  society  may  be  summed  up  as  the  granting 
to  each  individual  of  a  social  group  the  fullest  liberty  to  develop  and  utilise 
the  personal  energies,  under  the  guidance  of  moral  and  juridical  laws  that 
are  perfectly  equal  for  every  member  of  the  group,  along  with  the  protection 
of  labour,  in  any  form,  on  the  part  of  the  group.  The  liberty  (which  is 
disciplined)  and  the  protection,  taken  together,  give  the  measure  of  solidarity 
of  the  social  group  and  this  furnishes  elements  for  that  strong  social  and 
humanitarian  sentiment  which  is  still  in  course  of  evolution,  but  is  even  now 
strong  enough  to  play  a  part  in  the  composition  of  every  evolved  personality. 
These  elements  consist  essentially  of  the  experience  of  the  individual  in  his 


APPENDIX  TO  CHAPTER  IX  297 

personal  environment  and  the  historical  experience  of  the  group  (social 
ontogeny  and  social  phylogeny). 

The  evolutionary  process  is  not  equal,  nor  is  it  equally  progressive,  in  all 
peoples.  It  is  often  interrupted  by  periods  of  repose,  by  revolutions  and 
regressions.  Liberty,  with  co-operation  and  moral  discipline,  is  one  of  the 
stars  which  guide  the  triumphal  march  of  mankind.  Liberty,  however, 
may  have  obstacles  put  in  its  path.  Labour  may  be  enforced  or  it  may  be 
left  without  protection.  Again,  very  unequal  climatic  or  historical  con- 
ditions (political  institutions,  religion,  popular  education,  etc.)  may  so  bring 
it  about  that  too  wide  a  gulf  separates  the  most  advanced  elements  of  a 
people  from  the  least  progressive  members  who  have  had  to  live  and  struggle 
under  unfavourable  conditions  of  existence,  with  the  result  that  one  of  two 
things  happens.  Either  the  people  remains  oblivious  to  the  signs  of  the 
times,  learning  little  or  nothing  of  the  forward  march  of  other  peoples  and 
enduring  the  power  of  the  rich  and  educated  classes,  in  which  case  the 
character  of  the  popular  mass,  blind  and  deaf  as  it  were,  puts  a  stamp  of 
inferiority  upon  the  whole  social  group,  or,  again,  the  populace  feels  the  new 
impulses  propagated  from  afar,  like  seeds  borne  upon  the  wind  and  falling 
upon  receptive  soil — and  with  what  result  ?  Revolution,  with  all  its  horrors, 
all  its  excesses,  in  an  endeavour  to  level  outstanding  inequalities,  and  often 
with  a  complete  reversal  of  the  order  of  things,  which  makes  manifest  the 
silence  of  the  humanitarian  sentiment,  of  too  recent  growth,  in  the  evolution 
of  the  human  understanding,  to  be  capable  of  resisting  the  reactive  impulses 
of  the  crowd,  panting  for  the  recognition  of  its  rights  !  One  cannot  altogether 
agree  with  the  assertion  that  a  hierarchy  of  the  lower  as  against  that  of  the 
higher  classes  of  a  people  is  like  comparing  a  savage  and  primitive  race  to  a 
civilised  people ;  not  altogether,  because  when  the  mass  provides  a  higher 
hierarchy,  in  that  very  fact  lies  the  proof  that  it  possesses  the  potentiality 
of  a  rapid  evolution.  All  that  is  wanted  is  that  it  be  placed  in  conditions 
favourable  for  development  (education  and  protection  of  labour).  This  is 
the  commanding  duty  of  the  higher  hierarchy,  though  often  it  happens  that 
it  is  not  so  understood — e.g.  by  those  who  rule  over  us.  If,  owing  to  defect 
or  distortion  of  the  sense  of  civil  duty,  the  higher  hierarchy  fails  to  understand 
its  social  and  political  obligations,  and  presses  upon  the  lower  people,  we  will 
have  the  phenomenon  of  revolution,  which  at  bottom  is  only  the  reactive 
impulse  of  the  popular  consciousness,  aspiring,  it  may  be  somewhat  blindly, 
to  justice  and  more  favourable  conditions  of  existence,  as  against  the  tyranny 
of  autocracy  or  of  caste  and  against  the  stupid,  ignorant  presumption  of  those 
at  the  head  of  public  affairs  and  their  immediate  and  chief  instruments. 

It  is  different  with  savage  and  primitive  peoples  who  do  not  feel  the  new 
impulses  of  the  times.  In  their  case  the  sentiment  of  sociality  is  but  rudi- 
mentary and  limited  to  a  group  of  persons,  generally  not  very  numerous. 
Society  is  there  maintained  by  traditions  which  fix  determined  customs  and 
beliefs,  making  these,  as  it  were,  a  social  heredity,  which  remains  unopposed 
by  any  extraneous  element  of  advanced  civilisation.  If  new  elements  come 


298  THE  MECHANISM  OF  THE  BRAIN 

into  opposition  with,  and  become  gradually  substituted  for,  the  old  habits 
they  are  the  fruits  of  a  strong  perceptive  power  which  takes  stock  of  the 
environment ;  in  other  words,  they  are  the  result  of  new  acquisitions  and 
a  new  determinism.  Thus  do  innovations  and  variations  come  about. 
The  old  experience  becomes  substituted  by  the  experience  of  the  new 
adaptations,  more  in  accord  with  the  development  of  the  individual  and 
collective  personalities  and  more  promising  of  victories  in  the  struggle 
for  life. 

It  seems  clear  that  the  fundamental  factor  consists  of  an  understanding 
between  the  components  of  the  social  group ;  it  is  the  consonance  of  the 
manifestations  and  vicissitudes  of  the  life  of  all  in  the  mind  of  each ;  it  is 
painful  experience  of  one  reverberating  in  the  minds  of  all ;  it  is  danger  which 
concerns  one  individual  yet  is  felt  to  be  a  threat  to  all ;  it  is  sentiment  and 
imagination  allowing  the  whole  group  to  place  and  feel  itself  (less  intensely, 
no  doubt)  in  the  same  position  as  one  member  of  the  group  ;  it  is  the  sharing 
of  vicissitudes  that  affect  the  individual  or  are  common  to  the  lives  of  all ; 
in  all  of  which  there  is  a  basis  of  mutual  protection  and  co-operation  in 
aspirations  and  in  defence,  which  after  all  is  hedonism. 

One  can  readily  understand  that  all  the  components  of  a  group  do  not 
perceive  and  feel  the  impulses  to  a  new  situation  in  an  equal  degree.  Truly 
evolved  consciousness  is  the  possession  of  few  (Novikov),  but  two  factors 
come  into  play  which  tend  to  make  it  universal — suggestion  and  imitation. 
Progress  will  be  slow  by  evolution  or  by  hasty  bounds  through  revolution. 
According  as  the  variations  are  useful  so  the  new  experiences  are  substituted 
for  the  old,  and  the  social  bonds  are  constantly  being  drawn  closer  together 
because  the  benefits  obtained,  benefits  derived  from  the  inventions  of  few 
and  the  co-operation  of  many,  are  utilised  by  the  community  and  sometimes 
by  the  whole  of  humanity  (Baldwin,  Romanes,  Tarde,  Sergi,  Max  Nordau, 
E.  Meyer,  Linder). 

This  condition  creates  and  promotes,  as  has  been  said,  a  sentiment  which 
is  still  in  course  of  evolution.  It  had  its  roots  in  prehuman  and  savage 
communities  ;  it  developed  under  the  stimulus  of  some  religions  ;  it  received 
an  extraordinary  impulse  from  Christianity  but  it  is  to-day  being  transformed 
under  our  very  eyes  through  the  hedonistic  impulse  of  labour  and  co-operation. 

Everything  tends  to  show  that  this  sentiment  takes  shape  along  with 
the  development  of  the  frontal  lobe  and  with  the  corresponding  assimilation 
of  numerous  intellectual  elements.  The  latter  are  intellectual  syntheses 
which  are  essentially  bound  up  with  emotions  possessing  a  high  potentiality. 

It  has  been  said  (by  Sciamanna,  vide  Chapter  II.)  that  the  frontal  lobes, 
are  the  central  organs  of  the  emotions  because,  amongst  other  reasons, 
electric  excitation  of  these  organs  modifies  the  rhythm  and  frequency  of  the 
pulse,  the  blood-pressure  in  the  arteries,  the  respiration,  etc. ,  and  these  are 
organic  components  of  the  emotions.  In  point  of  fact,  there  is  nothing  that 
is  more  amply  contradicted  by  the  results  of  experiments  upon  monkeys  and 
of  extensive  lesions  in  the  frontal  lobes  of  the  human  subject.  The  truth  of 


APPENDIX  TO  CHAPTER  IX  299 

this  has  been  amply  demonstrated.  The  constant  phenomenon  presented  by 
monkeys,  and  even  dogs,  which  have  suffered  mutilation  of  the  frontal  lobes 
is  the  prototype  of  the  emotions — viz.  fear. 

Dogs  and  monkeys  have  drenched  themselves  with  urine  as  the  result 
of  a  threatening  impression  which  previously  caused  them  no  concern.  This 
symptom  coincides  with  the  well-known  fact  that  the  centres  of  the  organic 
phenomena  of  the  fundamental  emotions  are  localised  in  the  sigmoid  gyms, 
in  the  dog,  and  in  the  Rolandic  convolutions  in  monkeys  and  in  man.  Now 
if  the  emotions,  and  here  we  refer  to  the  primary  emotions,  persist  after 
removal  of  the  frontal  lobes,  and  if  man  becomes  more  excitable,  more 
emotional  and  more  impulsive,  in  consequence  of  severe  and  extensive 
lesions  of  the  frontal  lobes,  this  is  to  be  explained  by  the  fact  that  the  seat 
of  the  organic  phenomena  of  the  emotions  lies  not  in  the  frontal  lobes  but  in 
the  sigmoid  and  Rolandic  areas,  and  that  the  latter  have  not  been  involved 
in  the  experimental  lesion.  This  finding  has  been  confirmed  by  clinical 
experience  as  well  as  by  experimental  observation. 

The  emotional  excitability  is  increased  simply  because  removal  of  the 
frontal  lobes  weakens  the  intellectual- sentimental  powers  comprised  under 
the  terms  "associative  perception"  and  "inhibition."  If  experimental 
excitation  of  the  frontal  lobes  has  sometimes  produced  organic  symptoms  of 
emotion  there  is  a  ready  explanation.  The  strength  of  the  current  employed 
has  been  too  great,  with  the  result  that  there  has  been  diffusion  of  the  electric 
stimulus  to  the  cortical  zone  in  very  close  proximity,  excitation  of  which  produces 
precisely  those  modifications  of  the  circulation,  respiration,  and  of  the  bladder 
which  accompany  fear.  What  do  become  suppressed  by  extensive  bilateral 
frontal  lesions  are,  in  man,  social  sentimentality,  friendliness,  social  under- 
standing, the  sense  of  social  obligations  and  therefore  the  moral  sense,  the 
sentiment  of  duty,  true  love,  courage  and  the  inhibitory  and  regulative  power 
over  conduct,  and,  in  the  case  of  mutilated  monkeys,  the  rudimentary 
manifestations  of  some  of  these  attributes. 

There  is  no  doubt  that  various  criticisms  that  have  been  levelled  at  the 
doctrines  of  the  functions  of  the  frontal  lobes  have  not  been  dispassionate. 
The  critics  have  failed  to  make  distinctions.  They  have  evidently  wished 
to  believe,  and  to  make  others  believe,  that  the  functional  localisation 
described  was  absolute  and  circumscribed,  when,  in  point  of  fact,  it  was 
clearly  stated  that  in  its  specific  function  the  frontal  lobe  utilised  the  in- 
tellectual and  emotional  products  of  the  entire  brain.  They  allowed  too 
much  scope  to  prejudices  and  attached  too  little  consideration  to  the  immense 
difficulty  that  is  involved  in  detecting  and  recognising  the  phenomena  and 
in  associating  them  together  so  as  to  interpret  them  in  the  light  of  psychology, 
aided  in  turn  by  psycho-pathology. 

Sociality  has  constantly  become  suppressed  after  frontal  mutilations. 
That  semblance  of  friendliness  and  love,  which  appears  in  one  form  in  the 
dog  and  in  another  in  the  monkey,  is  only  the  embryo  of  the  mature  con- 
dition which  we  find  in  modern  civilised  man.  When  both  frontal  lobes  are 
severely  injured  in  the  human  subject,  or  when  these  organs  are  not  developed 


300  THE  MECHANISM  OF  THE  BRAIN 

(idiots  and  imbeciles),  similar  conditions  obtain.  Love  and  friendship, 
which  are  fundamental  sentiments  of  sociality  based  upon  reciprocal  pro- 
tection, co-operation,  etc.,  are  not  emotions  which  emanate  directly  from 
organic  modifications,  nor  must  they  necessarily  be  accompanied  by  those 
changes  that  constitute  the  organic  elements  of  the  primary  emotions. 
They  are,  rather,  sentiments  which,  though  they  germinate  and  have  their 
beginnings  in  these  primary  emotions,  have  nevertheless  come  to  belong  to 
the  more  purely  spiritual  aspects  of  mind — the  light  and  heat  of  the  higher 
consciousness.  Even  were  we  prepared  to  admit  that  excitation  of  the 
frontal  lobes  produces  the  fore-mentioned  modifications  of  the  organic 
functions  (an  admission  that  is  quite  at  variance  with  the  more  reliable 
findings,  summarised  in  the  chapter  on  emotions)  it  would  not  necessarily 
follow  that  we  should  have  to  regard  the  frontal  lobes l  as  the  "  central  organs 
of  emotion."  Bearing  in  mind  the  fact  that  there  are  points  on  the  frontal 
area  where  excitations  gives  rise  to  movements  of  the  eyes,  pupil  and  ear, 
movements  which  are  duplicates  of  those  produced  by  excitation  of  corre- 
sponding sensory  centres  in  the  visual  and  auditory  areas  (a  fact  which  led 
the  writer  to  express  the  opinion  that  they  are  related  to  the  processes  of 
attention,  inhibitory  and  evocative,  which  have  their  seat  in  the  frontal 
lobe),  one  would  be  fully  justified  in  advancing  the  hypothesis  1  that  the 
areas  which  give  rise  to  the  organic  phenomena  of  emotion  may  likewise  have 
duplicates  which  would  furnish  the  kinsesthetic  elements  in  a  higher  field 
of  emotion — in  other  words,  in  the  field  of  sentiments,  especially  the  most 
synthetic  of  these — the  social  sentiment — with  the  whole  train  of  in- 
tellectual syntheses  incorporated  with  the  emotions  and  consisting  of 
renunciations,  inhibitions,  social  obligations,  protection,  increased  benefits, 
etc.,  all  of  which  have  their  roots  in,  and  draw  their  vital  nourishment 
from,  the  kinsesthesis. 

Suppression  of  interest  and  curiosity,  leading  to  isolation  from  the  group 
— in  other  words,  disappearance  of  sociality,  characterised  by  indifference 
towards  the  social  environment  and  a  melting  away  of  all  manifestations 
of  friendship  and  attachment,  and  of  that  offshoot  of  sentimentality  that 
displays  itself  in  the  courting  of  the  sexual  instinct — are  facts  that  are  con- 
stantly observed  after  removal  of  the  frontal  lobes.  The  primary  emotions, 
the  appetites  and  the  instincts,  remain. 

This  experimental  condition  of  affairs  finds  a  counterpart  in  human 
psycho-pathology. 

If  it  is  true  that  primary  amentia  (idiocy  and  imbecility)  finds  its  explana- 
tion in  defective  evolution  of  the  frontal  lobes,  especially  the  pyramidal 
layers,  more  than  of  any  other  part  of  the  brain,  we  may  institute  a  perfect 
parallelism  between  the  mentality  of  the  monkey  that  has  suffered  frontal 
mutilation,  as  manifested  by  its  conduct  in  the  simian  environment,  and 
that  of  the  idiot  in  the  human  environment.  Timidity,  unsociability,  selfish- 
ness, the  absence  of  the  sentiment  of  friendship,  idleness,  laziness,  tics, 

1  Bianchi.  "  Sul  significato  dell'area  corticale  la  cui  eccitazione  produce  dila- 
tazione  della  pupilla."  Ann.  di  Nev.}  1916;  and  Archives  de  Biologie,  1917. 


APPENDIX  TO  CHAPTER  IX  301 

brutality  of  the  sexual  instinct  (when  present),  are  the  most  conspicuous 
features  of  idiocy  in  the  human  subject,  regarded  from  the  point  of  view  of 
sentimentality. 

This  condition  is  closely  linked  with  an  analogous  state  of  consciousness, 
more  particularly  moral  consciousness. 


NOTE 

To  the  writer  it  has  seemed  not  inopportune  to  add  this  appendix,  which  com- 
pletes the  picture  of  the  function  of  the  frontal  lobes.  It  does  not  pretend  to  be  an 
analysis  of  society,  much  less  a  dissertation  upon  the  various  doctrines  relating 
to  this  subject  that  have  been  expressed  from  time  to  time.  It  is  simply  the 
expression  of  some  thoughts  which  the  author  has  entertained  regarding  the 
physio-psychological  problem  of  sociality,  a  problem  which  he  believes  should 
rind  its  most  legitimate  interpretation  in  the  facts  brought  to  light  by  researches 
in  the  fields  of  anatomy,  experimental  physiology  and  human  pathology.  This 
is  a  point  upon  which  the  author  would  lay  stress,  because  of  its  bearing  upon 
methods  of  research  in  psychology.  Whilst  certain  exponents  of  social  science 
betray  great  liberty  of  thought  in  their  interpretation  of  social  phenomena,  the 
biologist  must  seek  to  come  forward  with  the  products  of  positive  inquiry  which 
bring  social  phenomena  and,  generally  speaking,  all  psychic  phenomena,  as  far 
as  possible,  within  the  domain  of  biology,  more  especially  morphology,  physio- 
logy, and  cerebral  cytotecture,  controlled  by  psychopathology  and  experiment. 


CHAPTER  X 

Consciousness 

"  To  us  positivists,"  writes  Morselli,1  "  consciousness  is  an  abstraction. 
Strictly  speaking,  there  exist  only  phenomena  and  facts  of  our  vital  activity 
as  conscious  beings ;  i.e.  we  are  conscious  of  them  because  we  perceive 
them  within  ourselves."  Consciousness  is  an  attitude  of  psychic  life  which 
is  stamped  by  the  particular  character  of  the  notions  that  are  constantly 
being  grafted  upon  the  kinsesthetic  stem,  and  by  the  sentiments  arising 
from  these  grafts  and  resolving  themselves  into  actions  the  story  of  which 
is  registered.  The  Ego  is  the  synthesis  of  the  life  and  the  cognitions  of  the 
individual,  it  is  a  unifying  activity  which  is  constantly  undergoing  renewal, 
under  the  action  of  external  agents  and  the  relations  that  are  ever  being 
established  with  the  consciousness  of  other  beings  with  whom  we  live  (social 
consciousness). 

The  anxious  endeavour  on  the  part  of  many  naturalists  and  psychologists 
to  settle  the  question  Where  exactly  in  the  scale  of  animal  life  the  dawn  of 
consciousness  can  be  detected,  or  to  fix  the  dividing  line  between  the 
Umbewuste  Denken  and  conscious  thought,  is  not  only  futile  but  needless, 
like  the  vain  endeavour  to  establish  a  line  of  separation  between  instinct 
and  reason.  Proceeding  from  phenomena  of  tropism  up  to  reason,  the 
nervous  processes  involved  are  all  found  to  be  of  the  same  nature.  The 
nervous  system  with  its  receptive  mechanism,  its  centripetal  paths,  its 
transforming  organs  (ganglia),  and  its  centrifugal  or  neuro -muscular  paths, 
is  built  up  on  the  same  system  in  all  creatures  provided  with  a  nervous  system. 
In  all  animals  complication  of  the  reactions  or  adaptations  is  proportionate  : 
(1)  to  the  degree  of  perfection  and  differentiation  of  the  receptive  sensory 
organs ;  (2)  to  the  increased  number  of  central  organs  which  act  as  trans- 
formers and  multipliers  ;  and  (3)  to  the  greater  possibilities  of  co-ordination 
of  the  motor  organs  by  means  of  which  living  creatures  react  upon  the  world. 
The  process  is  really  always  of  the  same  nature.  The  relative  invariability 
of  what  is  called  instinct  has  connection  with  the  simplicity  of  the  nervous 
apparatus  whence  emanates  the  life  of  relation.  Nevertheless,  variability 
of  the  instinctive  reactions  may  be  brought  about  by  variations  in  the 
environment  and,  in  the  higher  evolved  beings,  by  methods  of  education 
which  are  capable  of  causing  the  evolution  of  the  nervous  system  of  the  whole 
species  to  occur  more  rapidly,  though  the  process  always  remains  a  slow  one. 
Instinct  is  not  invariable,  nor  is  it  probable  that  the  mechanism  which  gives 
rise  to  it  is  immutable. 

What  has  been  called  "  unconscious  thought,"  or,  in  the  words  of  Lloyd 
1  Morselli.     "  I  liiniti  della  coscienza."     Rivista  di  filosofia.     1913. 

302 


CONSCIOUSNESS  .  303 

Morgan,  "  the  beginnings  of  a  rational  scheme/'  represents  in  the  zoological 
series  only  a  long  dawn,  the  scanty  and  pallid  light  of  which  does  not  permit 
full  and  accurate  observation.  It  is  followed  by  the  clear  morning  of  in- 
telligence in  the  higher  mammals,  more  particularly  the  primates,  then  by 
full  midday  sunlight  in  the  conscious  intelligence  of  modern  civilised  man, 
which,  too,  has  had  to  pass  through  phases  of  obscurity  and  penumbra. 
The  stronger  light  is  due  to  the  larger  number  of  nervous  elements,  and  their 
greater  development  and  differentiation,  and  is  the  more  intense  the  greater 
the  number  of  these  and  the  more  closely  they  act  together. 

It  will,  of  course,  be  understood  that  this  is  merely  a  provisory  formula, 
a  tentative  interpretation  which  may  serve  to  provide  a  more  intelligible 
conception  of  the  phenomenon  "  consciousness,"  which,  from  its  very  nature; 
must  ever  remain  shrouded  in  mystery.  It  is,  further,  to  be  observed  that 
we  know  little  or  nothing  of  the  life  of  relation  of  the  lower  creatures.  McCabe 
reports  an  incident  related  by  Jeannette  Power,  who  observed  an  octopus  in 
an  aquarium  carry  a  species  of  oyster  with  one  tentacle  and  a  stone  with 
another,  and  wait  for  the  oyster  to  open,  whereupon  the  octopus  immediately 
inserted  the  stone  between  the  valves  and  thus  was  able  to  devour  the  mollusc. 
This  action,  if  it  took  place  as  described,  presented  all  the  characters  of  reason. 
We  may  also  speak  of  it  as  an  adaptation,  but  the  preparation,  the  waiting, 
the  whole  complexity  of  the  reaction  permit  us  to  ascribe  to  it  attributes 
of  reason  or,  let  us  say,  unconscious  reason,  if  we  may  for  the  moment  make 
provisional  use  of  the  latter  term.  In  any  case,  we  can  agree  that  we  have 
here  a  nervous  mechanism  educated  by  experience  and  productive  of  a  result 
that  is  useful  in  life.  There  is  no  doubt  that  appropriate  mechanical  or  visual 
stimuli  give  rise  to  actions  that  seem  rational.  Take,  e.g.,  the  selection  of 
digestible  from  amongst  indigestible  material  made  by  the  limulus  from  which 
Loeb  had  removed  the  principal  ganglion  (supra-oesophageal) .  We  have  no 
standard  or  means  by  which  we  can  estimate  the  extent,  the  lucidity  or 
otherwise,  of  the  consciousness  of  other  creatures,  because  we  have  no 
counterpart  other  than  our  own  consciousness,  which  itself  is  variable  ac- 
cording to  time  and  circumstances,  and  therefore  cannot  serve  as  a  means 
of  measurement. 

All  that  can  safely  be  said  of  such  instances  is  that  the  behaviour  is  always 
logical,  whether  it  be  made  up  mostly  of  reflexes  or  mostly  of  psychism. 
The  bond  of  coherence  between  actions  is  one  of  the  most  universal  mani- 
festations of  life,  extending  from  chemical  affinities  to  tropisms,  from  these 
to  adaptations  occurring  with  unconscious  thought,  and  finally  to  conscious 
logic,  in  the  evolved  mental  world.  ., 

Consciousness,  though  not  a  faculty,  is  in  continual  evolution.  It  is 
a  very  variable  and  mutable  condition  pertaining  to  the  psychic  processes 
occurring  in  an  evolved  brain.  Its  field  lies  not  in  any  special  part  of  the 
cerebral  mantle,  but  in  the  whole  brain,  perhaps  in  the  entire  organism. 
It  evolves  along  with  life,  and  has  no  origin  other  than  in  life.  Its  evolution 
has  neither  end  nor  limitation.  Its  components  are  the  traces  of  the  organic 
movements  of  the  creature,  the  sensations,  emotions,  notions,  sentiments 


304  THE  MECHANISM  OF  THE  BEAIN 

and  reactions  in  the  most  varied  forms  of  adaptation.  It  may  be  restricted 
within  a  narrow  circle  of  cognitions  but  expands  with,  new  perceptions  of  the 
physical  environment  and  by  assimilating  the  energies  of  the  social  as  well 
as  the  physical  environment,  ever  gaining  in  scope  and  power  with  advances 
in  interhuman  relations  and  understandings.  All  biological  processes,  be 
they  chemical,  physical  or  mechanical,  play  a  part  in  its  development,  in 
so  far  as  they  represent  the  continual  motion  of  matter,  the  ions  of  which 
become  transformed  into  nervous  waves  from  the  very  moment  when  the 
nervous  system  first  makes  its  appearance  in  the  evolution  of  living  things. 
It  keeps  pace  with  the  evolution  and  the  complexity  of  living  organisms  and 
especially  with  the  development  and  complexity  of  the  nervous  system. 

Evolved  consciousness  has  certain  relations  with  time  and  space,  two 
very  important  elements  which  serve  to  complete  it.  The  conception  of 
time  and  space  is  only  arrived  at  through  the  intermediary  of  perceptive 
processes  infinitely  numerous  in  time,  and  through  the  immense  number  of 
small  spaces  measured  by  the  innumerable  movements  of  the  body  as  a  whole, 
of  the  hmbs  in  particular,  and  also  of  the  eyes.  The  consciousness  of  the  ego 
in  time  and  space  relates  but  to  one  moment  in  one  definite  space.  It  is, 
however,  susceptible  of  analysis  by  recalling  into  the  focal  point  the  whole 
succession  of  periods  of  time,  in  association  with  the  various  points  of  ren- 
dezvous in  the  story  of  the  individual  life — that  is  to  say,  the  main  incidents 
in  which  the  ego  was  interested.  All  times  and  spaces  cannot  be  represented 
separately  at  the  same  moment,  but  consciousness  has  the  power  to  make 
them  pass  through  its  focal  point  in  their  infinite  variety  like  a  biographic 
film.  All  that  is  not  represented  in  the  focal  point,  in  the  same  unit  of  time, 
constitutes  the  subconscious  and  this  part  of  the  mind  is  incomparably  larger 
than  the  illuminated  field. 

Where  and  when,  in  the  evolution  of  life  and  of  the  nervous  system, 
consciousness  begins,  is,  as  already  said,  a  futile  question.  To  seek  to  find  an 
answer  is  but  to  pursue  a  phantom  which  always  vanishes  as  we  step  forward 
to  grasp  it.  Psychologists  and  naturalists  long  made  of  this  theme  a  debating 
ground  for  the  most  difficult  and  delicate  mental  exercitations  ;  but  it  does 
not  come  within  the  scope  of  this  work.  In  their  endeavours  to  reconstruct 
the  natural  history  of  our  planet  and  the  story  of  lif  e,  naturalists  and  psy- 
chologists have  no  doubt  taken  advantage  of  all  the  newer  and  more  delicate 
instruments  of  investigation  which  the  modern  scientific  spirit  has  devised 
as  the  result  of  researches  in  the  fields  of  Anatomy,  Physiology,  Comparative 
Physiology,  as  well  as  Geology  and  Palaeontology  ;  but  the  problem  seems  no 
nearer  to  solution. 

It  is  necessary  that  we  come  to  an  understanding  as  to  the  extension  to 
be  assigned  to  the  conception  "  Consciousness. "  There  are  two  main  currents 
of  opinion.  According  to  one,  consciousness  is  to  be  regarded  as  the  light 
which  emanates  from  the  experience  of  the  ego,  in  the  acquisition  and  utilisa- 
tion of  cognitions  obtained  from  the  external  world.  If  we  accept  this  view 
we  agree  to  recognise  the  dawn  of  consciousness  in  the  mutable  adaptations 


CONSCIOUSNESS  305 

of  living  creatures  as  they  react  to  the  changing  circumstances  of  the  en- 
vironment, guided  by  the  past  experiences  of  the  individual  and  the  species, 
and  by  the  notions,  be  they  few  or  many,  which  the  creatures  comprised  within 
the  particular  category  acquire  through  the  perfecting  of  their  perceptive 
instruments.  According  to  the  other  view,  and  it  has  good  reason  to  support 
it,  we  must  conceive  consciousness  as  including  "  the  unconscious,"  which 
becomes  organised  with  the  vital  experience  of  all  beings  submitted  to  the 
action  of  the  forces  of  nature,  which  slowly  but  surely  modifies  them  and 
impels  them  onwards  to  the  light  of  consciousness.  In  this  case  the  limits 
of  consciousness  would  be  confused  with  those  of  animal  life — that  is  to  say, 
with  all  those  manifestations  which  to  outward  appearance  are  conscious 
and  volitional,  but  in  reality  are  nothing  else  than  the  effect  of  the  chemico- 
physical  action  of  external  stimuli  upon  the  protoplasm  (vide  Chapter  I.). 
It  is  from  the  tout  ensemble  of  the  chemico-physical  modifications  that  con- 
sciousness draws  the  elements  of  its  first  nucleus,  and  from  the  tout  ensemble 
of  these  its  raison  d'etre.  In  the  human  subject  it  draws  its  elements  more 
directly  from  the  unconscious,  just  as  in  the  story  of  life  the  consciousness 
of  the  higher  beings  appears  before  us  as  the  continuation  of  the  physico- 
chemical  reactions  of  the  lower  creatures. 

McCabe,1  in  a  recent  publication,  referring  to  the  suggested  possibility 
of  the  existence  of  the  senses  of  pleasure  and  pain  in  protozoans,  says  that 
"  we  may  speak  of  an  organic  analogue  of  feeling  in  the  protozoa  but 
there  is  no  ground  for  saying  that  it  is  not  a  physico-chemical  process." 
Max  Verworn  and  Loeb  refuse  to  recognise  any  true  psychic  manifestation 
in  the  various  phenomena  in  the  life  of  protozoans,  ccelenterates  and  worms.2 
R.  S.  Semon  3  made  an  accurate  study  of  a  group  of  echinoderms  and  came 
to  the  conclusion  that  there  is  no  trace  of  true  psychic  activity  in  these 
creatures.  Even  the  selection  of  food  from  amongst  digestible  and  indi- 
gestible material  may  be  merely  a  mechanical  response  to  chemical  or 
physical  stimuli  rather  than  a  matter  of  experience. 

There  is  no  doubt  we  cannot  speak  of  consciousness  and  volition  in 
these  creatures,  but  at  the  same  time  we  cannot  refuse  to  recognise  in 
the  phenomena  of  reaction  which  they  exhibit  a  slow  transformation  of  the 
physico-chemical  processes  into  unconscious  mental  processes. 

According  to  Loeb,  too,  the  circling  of  the  moth  around  a  lamp, 
sometimes  resulting  in  burning,  is  a  phenomenon  of  heliotropism  like  the 
bending  of  plants  towards  the  light,  just  as  the  collecting  of  palcemonetes 
at  the  anode,  when  subjected  to  the  passage  of  an  electric  current,  is  a 
phenomenon  of  galvanotropism.  It  is  neither  instinct  nor  curiosity  on  the 
part  of  the  moth  that  makes  it  fly  towards  the  light  but  a  chemical  action 
of  the  light  upon  its  protoplasm,  with  mechanical  effect.4 

1  McCabe.     The  Evolution  of  the  Mind.     London,  1910. 

2  Loeb.     Loc.  cit. 

3  R.  S.  Semon.     Beitrage  zur  Naturgeschichte  der  Synaptiden  des   Afittelmeers. 
Mittheilungen.     Bd.  vii. 

4  Loeb.     Comparative  Physiology  of  the  Brain  and  Comparative  Psychology. 

U 


306  THE  MECHANISM  OF  THE  BRAIN 

The  similarity  of  the  effects  produced  by  physical  agents  on  different 
organisms  (animals  and  plants)  would  indicate  that  the  latter  must  have 
some  property  in  common.  This  condition  would  be  fulfilled  by  the  presence 
in  all  of  them  of  some  substance  which  undergoes  a  chemical  change  when 
subjected  to  the  influence  of  light,  this  in  turn  giving  rise  to  changes  of 
tension  in  the  contractile  tissue.  In  the  same  way,  what  has  been  called 
instinct  on  the  part  of  the  females  of  certain  insects,  which  always  deposit 
their  eggs  on  substances  furnishing  food  for  the  larvae,  would  be  a  phenomenon 
of  chemiotropism — that  is  to  say,  the  action  of  the  insect  would  be  the 
chemical  effect  of  certain  molecules  which,  by  diffusion,  act  upon  cutaneous 
elements  and  on  the  tension  of  the  muscles,  including  those  of  the  genital 
organs  concerned  in  the  depositing  of  the  eggs. 

The  passage  to  a  more  illuminated  and  protective  reaction  is  gradual. 
Thus,  in  the  medusa,  the  rhythmical  movements  of  the  umbrella  in  loco- 
motion are  comparable  with  the  movements  of  the  heart  and  respiratory 
muscles,  in  which  no  one  pretends  to  see  the  elements  of  consciousness ; 
on  the  other  hand,  the  movements  of  reaction  which  the  medusa  performs 
with  the  manubrium  of  the  umbrella,  when  any  point  of  it  is  touched  with 
forceps,  are  markedly  more  complex  and  more  protective. 

Even  did  we  admit  that  these  movements  are  of  a  chemical  nature,  which 
is  much  more  probable  than  one  would  imagine,  although  the  chemical  fact 
has  not  yet  been  established,  we  witness  once  again  the  slow  and  confused 
passage  from  the  genuinely  chemico-physical  to  the  psychic  process  of  life, 
and  by  degrees  from  the  latter  to  the  facts  of  consciousness.  Were  it  sug- 
gested that  in  these  reactions  there  is  a  dawn  of  consciousness,  one  could 
not  strenuously  deny  it.  Lloyd  Morgan  expresses  the  opinion  that  a  dim 
consciousness  probably  accompanies  those  essentially  physico-chemical 
facts. 

In  molluscs,  e.g.,  we  find  a  marked  variety  and  complexity  of  move- 
ments, especially  in  the  pursuit  of  prey,  the  avoidance  of  capture  and  the 
courting  of  the  female,  and  at  the  same  time  more  fully  developed  and 
perfected  sense  organs,  and  larger  and  more  approximated  nervous  ganglia. 
Thus,  in  the  octopus,  the  eye  is  highly  developed,  and  the  ganglionic  and 
neuro-muscular  apparatus  makes  clear  the  reason  of  the  very  complex 
manifestations,  including  even  emotional  attitudes,  exhibited  by  this  creature. 
Such  behaviour  as  is  observed  in  the  octopus  already  presents  the  features 
of  a  more  highly  evolved  intelligence.  Not  that  this  should  signify  con- 
sciousness in  the  human  sense,  but  it  certainly  indicates  something  more 
than  a  simple  reflex.  Rather  would  it  represent,  in  the  words  of  Professor 
Lloyd  Morgan,  the  commencement  of  the  "  utilisation  of  experience  through 
the  exercise  of  intelligence/'  Utilisation  of  experience  coincides  with 
enlargement  of  the  nervous  mass  and  the  possibility  of  more  numerous 
associations  and,  accordingly,  of  combined  memory. 

We  have  already  mentioned,  in  Chapter  III.,  that  in  the  lowest  verte- 
brates belonging  to  the  fishes  (e.g.  the  lamprey),  the  brain  appears  as  a  small 
bulbous  expansion  situated  in  front  of  and  above  the  spinal  medulla,  whilst 


CONSCIOUSNESS  307 

in  the  dog-fish  it  is  a  highly  developed  and  complex  organ.  We  saw,  too, 
that  a  large  and  important  olfactory  organ  communicates  directly  with  the 
fore-brain,  which  is  no  more  than  represented  by  a  thin  layer — the  humble 
precursor  of  the  rich  mantle  of  the  higher  vertebrates.1 

We  can  now  recognise  in  a  general  way  a  parallelism  between  the 
development  of  the  nervous  system  and  the  evolution  of  intelligence  and, 
accordingly,  of  that  quality  of  mind  which  we  call  consciousness. 

Many  writers  (Romanes,  Brehm,  Zell,  Preyer,  Hobhouse,  Morgan)  discuss 
the  form  and  degree  of  intelligence  in  fishes  and  employ  such  words  as  these  : 
"  intelligence  and  consciousness,"  "  obscure  physiological  processes," 
"  organic  memory,"  "  unconscious  memory,"  "  unconscious  intelligence,"  etc. 

All  this  very  varied  nomenclature  shows  the  great  uncertainty  of  psychol- 
ogists and  naturalists  in  interpreting  the  actual  psychological  state  of  these 
inferior  creatures,  because  the  observer  cannot  always  abstract  himself  from 
his  own  states  of  consciousness,  in  judging  the  movements  and  reactions  of 
lower  creatures  subjected  to  the  influence  of  external  stimuli.  Were  it 
possible  for  us  to  abstract  ourselves  from  our  conscious  and  thinking  ego, 
and  could  we  picture  to  ourselves  a  diagram  of  the  psychic  complexes  involved 
in  the  life  of  the  different  orders  of  animals,  we  would  behold  the  perceptive 
line  and  the  reactive  line  ascending  regularly  and  keeping  parallel  with  the 
growth  and  perfection  of  the  sense-organs  and  the  central  nervous  system, 
except  for  certain  oscillations  which  cannot  as  yet  be  regularly  explained.2 
In  this  succession  of  creatures  in  the  evolutionary  scale  we  can,  in  a  manner, 
perceive  two  links  of  a  long  chain  connecting  the  physical  world  with  con- 
sciousness, as  Lugaro  3  puts  it  in  his  penetrating  criticism  of  philosophic 
systems. 

In  the  higher  fishes,  as  the  cerebral  mantle  develops  and  the  nerve-cells 
increase  in  number,  at  the  same  time  becoming  more  evolved  and  assuming 
more  numerous  relations  with  one  another,  the  psychic  life  makes  the  mantle 
its  organ,  and  there  now  appear  on  the  scene  emotional  manifestations 
which,  in  their  intensity  and  some  other  respects,  resemble  those  displayed 
by  mammals. 

Many  years  ago  the  writer  went  out  one  day  with  fishermen,  at  a  tunny 
fishery  near  Palermo.  Before  the  fishermen  began  to  haul  in  the  net  of  the 
so-called  "  death-chamber,"  which  that  day  held  more  than  700  fish,  all 
seemed  to  be  quiet  and  peaceful  amongst  the  captured  fish.  Immediately 
the  crew  commenced  to  haul  in  the  net  there  followed  a  state  of  agitation 
which  increased  each  moment  and  thrilled  the  spectator.  The  tunny-fish 
dashed  madly  about  in  all  directions,  knocked  against  one  another,  leaped 
out  of  the  water,  dived  below  again,  the  whole  performance  being  one  of 

1  Johnston.     Nervous  System  oj  Vertebrates.     1907. 

2  The  line  undergoes  interruption  and  even  inversion  on  passing  from  the  higher 
invertebrates  to  the  first  vertebrates  provided  with  a  cerebral  mantle.     Indeed,  the 
intelligence  displayed  by  some  insects  is  much  superior  to  that  of  the  cartilaginous 
fishes  and  even  higher  species.     An  explanation  is  set  forth  in  Chapter  III. 

3  Lugaro.     Modern  Problems  oj  Psychiatry.     1907. 


308  THE  MECHANISM  OF  THE  BRAIN 

convulsive  agitation.  Amongst  the  tunny-fish  there  happened  to  be  a  sword- 
fish,  which  at  first  was  calm,  then  became  seized  with  like  agitation,  and  as  we 
looked  we  saw  it,  in  an  accession  of  fear  or  excitement,  plunge  its  terrible 
weapon  into  the  body  of  a  large  tunny. 

How  is  this  intense  emotional  agitation  to  be  explained  ?  We  may 
possibly  set  it  down  to  chemical  action  arising  from  difficulty  in  breathing 
(the  restricted  space  of  the  meshed  net)  or  to  a  physical  factor  dependent 
upon  abnormally  close  contact  with  one  another ;  but  the  writer  cannot 
exclude  an  intuitive  fear  of  danger  in  the  new  and  strange  situation  in  which 
the  fish  found  themselves.  Shall  we  ascribe  it  to  intelligence  in  the  human 
sense  ?  No,  because  there  is  no  proof  of  a  clear  perception  of  the  situation  ; 
nor  can  we  even  speak  of  consciousness,  because  consciousness  implies  per- 
ception and  memory.  It  is  something  which,  though  not  entirely  free  of  the 
chemical  or  physical  or  mechanical  element,  such  as  is  found  in  the  mental 
life  of  creatures  with  a  more  rudimentary  nervous  system,  we  can  never- 
theless figure  to  ourselves  as  a  step  in  the  ascending  scale  of  development 
of  intelligence  and  consciousness. 

With  the  constant  growth  of  the  nervous  system,  organic  becomes 
associative  memory. 

As  we  cannot  conceive  of  intelligence  without  memory  of  associated 
images — for  even  the  perceptive  process  (of  recognition)  is  based  upon 
memory — consciousness  may  be  regarded  as  a  synthesis  of  memories 
and  their  combinations. 

If  memory  of  the  organic  modifications,  determined  by  the  succession 
of  stimuli  acting  upon  the  surface  of  the  body  and  on  the  different  senses, 
is  an  indispensable  condition  of  intelligence,  it  also  seems  clear  that  associative 
memory  is  the  basis  of  consciousness.  At  the  level  of  instinct,  associative 
memory  is  static  and  uniform,  or  almost  uniform,  and  for  this  reason  we  exclude 
consciousness,  which  involves  movement  of  the  multiform,  conflict  and  choice. 

With  multiplication  of  the  organs  of  life,  with  their  constantly  increasing 
differentiation  and  perfection  as  we  rise  in  the  animal  scale,  we  obtain  the 
constituent  elements  of  consciousness  to  which  are  added,  in  the  human 
subject,  the  images  of  one's  own  body  provided  by  visual  sensations,  by 
frequently  repeated  tactile  sensations,  by  the  sound  of  the  voice,  by  the 
performance  of  movements  and  the  experience  of  one's  own  force  acting 
against  resistance,  by  the  feeling  of  well-being  or  ill-being,  and  other  obscure 
components.  Amongst  the  latter  must  be  mentioned  the  chemical  processes 
of  the  organic  interchange,  secretory  movements,  movements  of  the  stomach 
and  intestines,  movements  of  circulation  and  respiration,  etc.  All  these 
fundamental  and  vital  functions,  with  their  accompanying  movements, 
furnish  additional  elements  of  consciousness  in  evolved  organisms,  elements 
that  are  not  apparent  but  are  none  the  less  important.  The  nucleus  of  the 
organic  ego  enlarges  with  the  more  differentiated  intuition  of  the  physical 
ego  and  its  own  peculiar  features,  and  with  all  the  organic  modifications 
caused  by  external  stimuli,  which  at  the  same  time  furnish  the  objective 
material  for  associative  memory. 


CONSCIOUSNESS  309 

It  should  be  quite  clear  that  the  phenomena  of  consciousness  cannot  be  ex- 
pressed in  terms  of  a  quantitative  denominator  which  will  serve  as  a  standard 
for  measurement,  as  in  the  other  forces  of  nature.  Any  attempt  in  this 
direction  based  upon  introspective  methods  of  investigation  yields  at  most 
some  reflex  bearing  of  the  objective  fact  upon  the  subjective  phenomenon, 
which  it  is  quite  impossible  to  submit  to  any  process  of  measurement. 

The  writer  would  put  forward  the  hypothesis  that  whilst  consciousness 
has  its  nucleus  in  sensations  and  organic  movements  and  doubtless  may  be 
fashioned  in  different  manner  in  different  beings,  yet  evolved  consciousness 
emanates  from  the  rencontre  of  the  actual  perception,  or  its  representation, 
with  other  confirmatory  or  contrasting  percepts  furnished  by  the  memory  of 
previous  states  of  consciousness,  conserved  in  the  unconscious. 

In  other  words,  it  would  be,  as  it  were,  the  light  which  emanates  from 
the  fusion  of  actual  images  with  mnemonic-traces  that  are  analogous,  allied, 
and  at  the  same  time  confirmatory  of  the  reactive  determinism,  or  from 
the  conflict  between  the  determinism  arising  from  actual  sensations  and 
images  and  an  opposite  determinism  arising  from  contrasting  memory -images 
which  are  recalled,  in  accordance  with  the  law  of  resemblance  and  contrast 
(associations) ,  from  the  capital  of  personal  experience.  Conflict  and  contrast 
are  significant  of  a  large  store  of  utilisable  mental  capital,  and  appear  to  be 
the  really  characteristic  features  of  an  illuminated  consciousness. 

It  would  accordingly  be  wrong  to  compare  the  consciousness  of  animals, 
even  the  more  highly  evolved,  with  that  of  man,  and  to  think  that  human 
consciousness  is  equal  in  all  men.  The  capital  of  notions  and  experiences, 
the  faculty  of  recalling  these  in  the  changing  circumstances  of  life,  the 
quantum  of  emotion  accompanying  a  sensation  or  its  representation,  the 
effects  of  more  or  less  vigorous  reactions  or  of  abstention  from  action,  which 
is  sometimes  a  result  of  interference,  give  the  pitch  of  consciousness  inas- 
much as  this  is  an  expression  of  many  factors,  which  either  sum  themselves  to- 
gether or  come  into  conflict  with  one  another,  and  of  the  quantity  of  light  and 
heat  (metaphorically  speaking)  which  emanates  from  the  process  in  question. 

A  great  part  of  our  mental  life  goes  on  outside  the  field  of  irradiation  of 
that  light,  for  the  greater  number  of  notions  and  experiences  is  conserved 
in  the  vast  dominions  of  the  unconscious  memory.  There  is  good  reason  to 
suppose  that  in  the  majority  of  lower  animals  conduct  occurs  without  internal 
conflict,  being  determined  by  actual  sensations,  representations,  and  emotions 
that  correspond  with  very  simple  nervous  mechanisms,  simple,  i.e.,  as 
compared  with  the  human  nervous  system.  It  is  clear  that  with  perfecting 
of  the  senses  and  growth  of  the  nervous  mass,  the  conduct  (reaction  upon  the 
environment)  of  living  beings  becomes  always  more  varied  and  multiform, 
more  protective,  and  supported  by  a  stronger  framework  of  logic.  As  logic 
develops  by  a  rigid  process  of  assimilation,  dissimilation  and  elimination  of 
elements  of  thought,  consciousness  culminates  in  deliberation,  just  as  this  is 
derived  from  the  judgment  of  convenience  resulting  from  impulsions  and 
inhibitions  (conflict).  If  I  prevent  my  dog,  a  very  intelligent  animal,  from 


310  THE  MECHANISM  OF  THE  BRAIN 

taking  a  piece  of  meat  and  then  go  away  with  forbidding  and  threatening 
air,  leaving  it  beside  the  dog,  he  refrains  from  touching  it.  Such  behaviour 
represents  an  inhibition  resulting  from  the  internal  struggle  between  hunger, 
desire,  the  impulse  to  eat  the  piece  of  meat,  and  the  prohibition  received. 
It  is  conscious  behaviour.  Numerous  representations  take  part  in  the 
particular  state  of  consciousness  involved  therein ;  these,  in  conjunction, 
give  rise  to  the  sentiment  of  obedience,  based  upon  fear,  which  in  turn  is  an 
experiential  biophylactic  product,  the  outcome  of  relations  with  his  master. 
If  desire  and  hunger  gain  the  upper  hand  and  the  dog  seizes  and  eats  the 
meat  and  then,  very  repentant  and  fearful,  hides  himself  or  runs  a  long  way 
off,  only  to  return  home  after  some  time,  full  of  compunction  and  humiliation 
and  imagining  that  he  will  have  to  confront  his  master's  displeasure, 
this  is  consciousness,  made  up  of  memories,  associations,  imagination  and 
sentiments  (similar  instances  are  recorded  by  Romanes). 

If  an  elephant  (case  of  Romanes)  already  laden  for  the  journey,  and  tied 
to  a  tree  by  his  conductor,  who  had  cooked  a  large  potful  of  rice  to  serve 
as  food  during  the  journey,  undoes  the  knot  of  the  rope  with  which  it  is 
tied  to  the  tree,  approaches  the  pot,  takes  off  the  lid,  eats  the  rice,  then,  to 
deceive  its  master,  returns  to  the  tree  and  again  ties  the  rope  round  it  so 
that  it  is  fixed  as  before,  all  this  operation  is  conscious  because  it  embraces 
perceptions,  emotions,  desire,  imagination  and  elements  of  contrast  drawn 
from  past  experiences  of  its  relations  with  its  master,  and  of  the  means  and 
methods  of  correction  employed  by  the  latter  during  the  period  of  its  training. 
The  elephant  had  a  prevision  (representation)  of  stern  correction,  but  judged 
that  it  could  avoid  it,  imagining  that  it  might  deceive  its  master  by  re-tying 
the  rope  to  the  tree. 

It  is  only  in  some  such  fashion  that  we  can  arrive  at  a  fairly  probable 
conception  of  consciousness.  If  we  eliminate  the  elements  summation  and 
conflict  from  the  conception  of  the  reactive  determinism,  we  shall  have  to 
accept  the  doctrine  of  Romanes,  Preyer  and  others,  who  assume  that  con- 
sciousness coincides  with  all  psychic  manifestations,  no  matter  what  their 
degree  or  their  -extent. 

If  one  should  feel  repugnance  in  recognising  the  phenomenon  conscious- 
ness in  psychic  acts  which,  though  apparently  motived  and  characterised  by 
reason,  are  nevertheless  derived  from  simple  and  almost  invariable  nervous 
mechanisms,  one  can  fall  back  upon  the  hypothesis  of  two  consciousnesses : 
(1)  primary  consciousness,  which  is  coextensive  with  psychism  in  all  its 
evolutionary  phases,  and  (2)  what  may  be  called  higher  consciousness,  the 
dawn  of  which  coincides  with  the  appearance  of  conflict  between  actual 
images  and  those  furnished  by  the  memory  of  past  experience. 

It  is,  of  course,  to  be  clearly  understood  that  there  is  no  clear  demarcation 
between  primary  consciousness — which  comprises  all  the  lower  mental  mani- 
festations, including  those  called  instincts  and  tropisms—  and  higher  con- 
sciousness. Both  of  these  may  be  represented  as  situated  on  one  line 
symbolising  the  evolution  of  animal  life. 

Parallel  with  this  line  we  can  picture  to  ourselves  another,  the  segments  of 


CONSCIOUSNESS  311 

which  represent  nervous  structures  in  all  their  grades  from  the  simplest  to  the 
most  complex — i.e.  to  those  that  are  richest  in  nervous  elements,  those  that 
represent  the  organ  of  the  higher  form  of  consciousness  emanating  from  the 
sum  of  past  experiences  re-evoked  and  represented  alongside  of,  and  in  com- 
parison with,  the  actual  situation,  experiences  which  generally,  or  at  least 
initially,  contain  an  affirmative  element  or  else  one  that  is  in  conflict  with  the 
actual  perceptions  and  correlative  impulses. 

The  contrasting  memory-images  in  conjunction  with  their  respective 
emotional  states  represent  both  individual  and  collective  experience.  It  is 
this  that  affords  the  true  standard  as  regards  adaptations  of  the  individual 
to  his  environment  for  purposes  of  defence,  maintenance  of  integrity,  and 
further  evolution.  The  writer  cannot  therefore  agree  with  Exner  when 
he  asserts  that  consciousness  is  a  group  of  representations  pre-existing 
in  the  cortex,  into  which  there  enters  a  new  representation  (perception). 
Even  lower  animals,  such  as  insects  and  birds,  give  undoubted  evidence 
of  possession  of  images  and  memories  to  which  are  added  actual  images, 
yet,  notwithstanding,  many  naturalists  and  psychologists  define  the  re- 
actions resulting  from  these  as  an  effect  of  instinctive  processes  depend- 
ent upon  comparatively  simple  nervous  structures  which  do  not  allow 
of  variations. 

Everything  considered,  consciousness  in  the  narrowest  sense  shows 
progressive  development  with  the  evolution  of  the  brain — i.e.  with  the 
constantly  increasing  number  of  image-records  which,  along  with  new 
perceptions  and  the  emotional  modifications  accompanying  them,  con- 
stitute an  organic  experience.  This  is  almost  systematised  where  the 
nervous  centres  are  still  comparatively  simple,  offering  no  scope  for  new 
co-ordinations. 

When  the  nervous  centres  become  more  complicate  the  perceptions  are 
more  perfect  and  more  numerous,  the  memory  more  faithful  and  more  certain, 
the  associations  more  complex  and  more  abundant,  experience  more  extensive 
and  further  reaching  ;  and,  in  addition  to  impulsive  images  and  more  ample 
and  varied  confirmatory  associations,  there  appear  upon  the  scene  others  of 
an  inhibitory  nature,  these  being  derived  from  painful  and  disintegrative 
experience  as  opposed  to  that  which  makes  for  the  integration  of  the  organism. 
It  is  quite  clear  that  consciousness  in  this  case  assumes  another  character, 
the  mental  processes  become  illuminated  with  a  new  light,  and  conduct, 
which  is  the  reflex  of  consciousness,  now  appears  as  the  resultant  of  impulsive 
and  inhibitory  forces. 

Those  reactions  which  are  the  outcome  of  impulsions  to  action  on  the 
one  hand  and  contrasting  inhibitions  on  the  other,  reactions  which  we  can 
observe  even  in  the  higher  mammals,  warrant  us  in  speaking  of  the  dawn  of 
a  higher  consciousness,  and,  if  we  trace  the  various  stages  in  the  evolution 
of  the  brain,  we  find  that  they  first  show  themselves  coincidentally  with  the 
first  appearance  of  frontal  lobes.  All  the  information  that  has  been  gathered 
from  observations  and  practical  experiments  goes  to  prove  that  the  successive 
developments  of  the  hind  brain  do  not  alone  suffice  for  manifestations  of 


312  THE  MECHANISM  OF  THE  BRAIN 

higher  consciousness.  It  seems  evident  that  there  are  required  the  presence 
and  collaboration  of  another  cerebral  organ  of  recent  development  which 
sums  up,  fuses,  transforms  and  regulates  the  immense  mental  capital  prepared 
by  the  hind  brain.  This  organ,  as  may  be  inferred  from  what  has  hitherto 
been  said  in  this  volume,  is  the  frontal  lobe. 

McCabe,1  after  recounting  examples  of  new  intellectual  manifestations  in 
dogs,  cats  and  other  mammals,  commonly  noted  for  their  astuteness  and 
for  acts  which  pass  beyond  the  bounds  of  instinct,  does  not  give  a  definite 
answer  to  the  question  whether  or  not  lower  animals  have  the  power  of 
reasoning.  Evidently  the  same  question  has  to  be  repeated  in  the  case  of 
reason  as  in  that  of  consciousness — "Where  does  it  commence?"  We 
cannot  shut  our  eyes  to  the  all-important  fact  that  stands  out  clearly  in  the 
story  of  the  evolution  of  living  creatures — viz.  that  reason  is  evolved  from 
simple  physico-chemical  processes  and  is  based  on  the  same  laws  of  affinity 
that  apply  to  these.  Reactions  are  but  the  reflex  of  stimuli.  In  that  reflex 
lies  the  germ  of  reason.  Just  as  the  associations  and  the  associative  memory 
become  more  complicated  with  the  evolution  of  the  nervous  system,  so  do 
the  reasonings  and  the  external  responses  of  living  creatures  become  more 
complex.  All  speculations  on  this  subject  on  the  part  of  a  large  number 
of  observers,  mostly  English  and  American — e.g.  Hobhouse  and  Thorn- 
dike — are  but  subtle  and  laborious  exercitations  in  a  field  without  limits, 
in  which  imagination,  linguistic  artifices  and  arbitrariness  seem  to  present 
no  obstacles.  From  the  consciousness  of  the  dog  to  that  of  the  Tasmanian 
(such  as  the  Sussex-man,  now  out  of  existence),  from  the  Tasmanian  to  the 
Hottentot,  from  the  latter  to  the  modern  uneducated  European,  and  pro- 
gressively to  the  average  educated  European  and  the  man  of  exceptional 
talent,  there  is  simply  an  ascending  scale  of  consciousness  in  the  wider  sense 
of  the  term. 

It  is  apparent  that  the  unity  which  we  are  apt  at  first  to  ascribe  to  con- 
sciousness is  fictitious.  Consciousness  really  varies  with  the  intellectual 
content  and  mode  of  feeling  in  each  individual  and  each  social  group  at 
different  periods  of  time.  In  the  ever-changing  content  of  consciousness  we 
must  recognise  an  inequality  of  the  unity  of  the  thinking  being,  which  the 
individual  recognises  in  himself  and  in  his  story  from  changes  of  sensations, 
emotions  and  images. 

In  highly  evolved  individuals  or  evolved  social  groups  consciousness 
tends  towards  sublimation.  In  this  fact  lies  the  proof  of  its  evolution. 
Examples  have  been  provided  by  certain  peoples  in  the  present  terrible 
period  of  history,  but  in  expressing  this  opinion  the  writer  will  not  venture 
one  step  beyond  what  is  human.  He  can  imagine  the  inventive  spirit,  the 
spirit  of  sacrifice,  of  heroism  and  of  all  the  other  virtues,  to  be  the  effect  of 
a  felicitous  spiritual  (cerebral)  evolution  which  transports  man  beyond  the 
limits  and  domains  of  personal  interest  into  those  recognised  as  social  interests 
which  are,  amongst  other  things,  the  ideals  of  science,  and  should  be  likewise 

1  McCabe.  LOG.  cit. 


CONSCIOUSNESS  313 

the  ideals  of  politics.*  Such  organisations  evidently  represent  something 
that  is  superior  to  the  ordinary  higher  consciousness ;  but  neither  imagina- 
tion nor  the  author's  positivistic  conception  of  consciousness  will  allow  him 
to  accept  the  conception  of  Myers 1  and  of  James  2  as  to  the  existence  of  a 
higher  consciousness,  in  the  sense  of  a  sublimed  ego,  alongside  the  actual  ego 
but  quite  without  the  human  organism. 

Here  we  enter  into  the  realm  of  subjectivism  and  of  creeds,  which  is  a 
domain  reserved  for  philosophical  speculation. 

In  studying  states  of  arrested  cerebral  evolution  in  man,  as  exemplified 
in  the  numerous  class  of  idiots  and  imbeciles,  we  can  retrace  the  story  of  the 
evolution  of  consciousness,  laying  bare,  in  a  retrogressive  fashion,  all  the 
various  phases  of  development  down  to  that  of  the  lower  monkeys.  Further, 
it  is  easy  to  detect  a  very  close  relationship  between  the  qualities  and  extent 
of  consciousness  on  the  one  hand,  and  the  number  of  cerebral  cells,  the 
greater  or  less  degree  of  arrest  of  their  structural  evolution,  and  the  number 
of  their  fibrillary  relations  on  the  other. 

Human  pathology,  and  more  especially  teratology,  plays  a  part  similar 
to  that  played  by  geology  and  palaeontology.  Pathology  and  teratology 
lay  bare  the  various  strata  in  the  ancient  morphological  and  psychic  forma- 
tions of  man,  whilst  geology  and  palaeontology  bring  into  evidence  the 
different  phases  in  the  formation  of  the  earth  and  of  the  life  which  it  supported 
for  millions  of  years  in  very  varied  forms  of  organisms  that  have  now  entirely 
disappeared. 

In  studying  idiots  and  imbeciles  we  can  retrace  the  natural  history  of 
human  and  prehuman  evolution  by  following  the  various  phases  of  dis- 
solution induced  by  disease.  By  psychological  investigation  of  repre- 
sentatives of  various  degrees  of  imbecility  and  idiocy  arising  from  defective 
or  incomplete  histo-morphological  evolution  of  the  brain  (as  distinguished 
from  that  caused  by  inflammatory  and  destructive  processes  affecting  different 
cerebral  provinces),  we  come  to  form  a  naturalistic  conception  of  conscious- 
ness as  a  mode  of  evolved  mentality,  a  conception  that  is  supported  and 

*  In  the  course  of  a  conversation  with  a  great  politician,  little  loved  during  his 
life,  much  regretted  after  his  death,  the  author  heard  with  his  own  ears  these 
very  words  :  "  Don't  talk  to  me  of  moral  reasons  in  this  or  any  other  question  ; 
politics  cannot  obey  moral  laws."  The  writer,  on  the  contrary,  maintains  that 
politics,  which  sums  up  the  thought,  sentiments  and  tendencies  of  a  people,  and 
illuminates  the  life  of  a  country,  cannot  on  any  account  claim  exemption  from 
moral  and  legal  obligations.  The  fact  is  that  the  conceptions,  tendencies  and 
creative  work  of  politics  are  often  distorted  by  personal  interests  a"nd  ambitions. 

Consider  the  social  aggregate  (which  to  the  writer  is  primarily  the  State)  "  as 
a  mere  numerical  sum  of  indifferent  individuals  "  (worse  still  if  egoistic)  "  who  will 
be  followed  by  other  individuals,  and  heroism,  sacrifice  pure  and  simple,  without 
possible  or  assignable  compensations,  can  no  longer  be  explained."  3 

1  Myers.     Human  Personality  and  its  Survival  of  Bodily  Death.   1902. 

2  James.     Philosophy  of  Experience. 

3  F.  Orestano.      "  Un  tragico  esperimento  di  verita  morali."      Nuovo   Convito. 
1918. 


314  THE  MECHANISM  OF  THE  BRAIN 

illuminated  by  the  histo-morphological  findings  in  different  brains  belonging 
to  individuals  who  displayed  different  degrees  of  mind-power.  Not  only  so, 
but  we  can  detect  arrests  of  evolution  in  all  stages  of  the  development  of 
language,  down  to  simple  monosyllabic  and  vowel  manifestations,  and  in 
the  development  of  thought,  if  we  have  regard  to  its  quality,  its  quantity, 
its  structure,  and  its  reactive  reflexes,  which  are  exceedingly  simple, 
inconclusive  and  illogical. 

Consciousness,  where  normally  and  happily  constructed,  varies  as  already 
indicated  around  a  permanent  and  stable  nucleus.  This  nucleus  is  char- 
acterised by  a  determinate  manner  of  feeling,  by  a  particular  orientation 
towards  certain  objects,  and  by  great  resistance  of  the  psychic  compounds 
to  the  disintegrating  action  of  the  storms  of  life,  whilst  at  the  same  time  it 
confers  a  more  rigid  directive  upon  life,  in  its  interhuman  relations.* 

This  nucleus  is  indeed  the  framework  of  character.  Great  wealth  of 
notions  and  images,  with  their  corresponding  emotional  states,  no  doubt 
renders  the  consciousness  unstable,  but  not  its  nucleus.  Just  as  protoplasm 
is  renewed  within  the  cell  without  the  latter  losing  its  chemical,  morphological 
and  functional  characters,  so  the  renewal  and  even  rapid  flow  of  ideas  in 
consciousness  leave  it  unperturbed  in  its  structure,  its  general  tone,  and  its 
function,  as  an  element  of  the  social  organism.  Again,  the  more  resistant 
and  the  more  attuned  to  general  principles  is  the  collective  consciousness 
of  a  people,  the  more  fortunate  is  it  for  the  country  which  produces  it. 

Movement  of  simple  images  and  of  ideas  through  the  focal  point  of 
consciousness  is  one  of  the  conditions  of  normal  mental  life. 

Some  psychologists  have  drawn  a  happy  parallel  between  the  movement 
of  ideas  and  groups  of  ideas  in  the  illuminated  field  of  consciousness  and  the 
motions  of  planetary  systems.  Just  as  the  stars  describe  their  orbit,  so  the 
ideative  systems  move  across  the  illuminated  field  of  consciousness ;  as 
the  greater  and  lesser  stars  maintain  reciprocal  relations  with  one  another, 
regulated  by  the  laws  of  gravity,  so  also  do  the  ideative  systems,  which  are 
regulated  by  the  constant  laws  of  association.  Just  as  the  planetary  systems 
seem  to  rise  and  sink  again  into  the  infinity  of  space,  so  ideas  rise  into  the 
light  of  consciousness,  and,  having  described  their  orbit,  sink  again  into  the 
unconscious.  The  stars  of  greater  magnitude  and  brilliancy  have  often  their 
satellites,  and,  similarly,  the  more  resplendent  ideas  attract  around  them  a 

*  It  is  only  in  this  sense  that  one  can  imagine  unity  and  continuity  of  conscious- 
ness. "  Each  of  us  becomes  aware  of  it,"  writes  De  Sarlo,1  "  as  something  to 
which  the  whole  of  our  experience  is  referred,  as  a  unit  common  to  a  multiplicity  of 
functions,  as  something  which  remains  steady  notwithstanding  the  flow  of  things. 
There  is  nothing  of  the  transcendental  in  our  conceptions.  There  is  a  historical 
continuity,  in  so  far  as  the  ego  can  follow  and  sum  up  all  the  variations  of  its 
existence,  punctuated  by  infinite  changes  both  of  the  kinsesthetic  sense,  owing  to 
severe  internal  alterations,  and  of  the  external  environment,  which,  too,  is  variable, 
mutable  and  discontinuous. 

xDe  Sarlo.     Psicologia  e  Filosofia.     Florence,  1918. 


CONSCIOUSNESS  315 

smaller  or  larger  number  of  other  ideas,  and  constitute  associative  systems 
or  fields  which  give  a  particular  intonation  to  the  mental  life,  impressing 
a  diverse  direction  on  the  wheel  of  fortune  of  each  man  or  each  human 
group. 

We  must  thus  recognise  a  continuous  dynamism  in  consciousness,  whereby 
the  ideas  and  sometimes  also  the  attitudes  of  mind  are  ever  being  renewed. 
We  cannot  conceive  a  static  condition  of  mind  except  during  periods  of 
exhaustion  or  of  ecstasy,  or  under  conditions  that  are  distinctly  morbid,  as 
in  the  case  of  stupor,  catatonia,  the  somnambulistic  condition,  etc.  It  very 
often  happens  that  a  thought  presents  itself  on  the  horizon  of  consciousness, 
dim  and  indistinct  in  outline.  By  degrees  it  assumes  a  concrete  form, 
becoming  always  more  illuminated,  attracting  around  itself  a  larger  or 
smaller  number  of  notions  and  ideas  and  occupying  consciousness  for  a  certain 
period,  only  to  fade  and  sink  away  again  after  a  time.  As  the  earlier  notions 
are  sinking  into  the  ocean  of  oblivion  new  systems  are  arriving  at  their  zenith, 
whilst  others  are  springing  up  on  the  opposite  horizon.  The  older  notions 
may  subsequently  make  their  appearance  again  from  time  to  time,  some  of 
them  in  a  constantly  rhythmic  fashion,  others  at  irregular  intervals  ;  occasion- 
ally they  nit  through  consciousness  like  comets,  or  they  make  their  appearance 
only  in  the  great  cataclysms  of  the  mind,  or  again  they  remain  in  the  back- 
ground of  consciousness  ready  to  show  themselves  anew,  and  even  in  the 
hiding-places  of  the  unconscious  they  may  conspire  in  secret  and  determine 
a  correlative  action. 

The  image  which  flatters  and  cajoles,  the  thought  which  takes  possession 
of  us  and  transports  us  into  the  infinity  of  the  unknown,  into  the  uttermost 
corners  of  the  consciousness,  into  the  bowels  of  the  earth,  or  into  the  depths 
of  the  ocean,  all  owe  their  appearance  in  consciousness  to  that  ceaseless 
dynamism  that  is  concerned  therein  ;  nor  is  consciousness  stable  as  regards 
emotional  states,  for  these  also  follow  one  after  another  and  evolve  with 
experience  of  life,  especially  through  the  interhuman  relations  which  each 
man  assumes.  With  growth  of  the  sentiment  of  understanding  between 
different  minds,  many  or  few,  near  or  distant,  according  to  the  constitution, 
degree  of  culture  and  affective  capacity  of  each  individual,  and  the  nature 
of  the  work  produced,  there  spring  up  emotions  and  sentiments  which  aid, 
vitalise  and  utilise  that  fundamental  sentiment  of  sociality  which  is  the 
turn-key  of  the  conduct  of  modern  civilised  man,  giving  a  particular  tone 
to  consciousness. 

Desire  which  spurs  one  on,  with  its  accompanying  images  of  things,  and 
sometimes  makes  one  chafe  and  fret ;  feelings  of  attachment  that  beget 
enthusiasm  and  raise  the  potential  of  the  spirits  ;  passion  which  burns  and 
subdues,  disrupting  the  individual  or  collective  system  of  life ;  fear  with  its 
morbid  fancies,  which  chill  the  ardour  as  a  frost  nips  the  buds  in  springtime, 
dispelling  Nature's  sweet  promises,  all  pregnant  with  beauty  and  throbbing 
with  hope ;  pain  which  bows  one  down ;  pleasure  which  laughs  with  light 
and  careless  heart,  enjoying  every  day  of  existence ;  hatred  which  plots  and 
undermines  ;  envy  which  in  its  impotence  eats  out  the  soul  or  makes  hidden 


316  THE  MECHANISM  OF  THE  BRAIN 

attack  with  the,  weapon  of  calumny ;  love  which  transports  one  into  the 
flowery  fields  of  pleasure,  enthusiasm  and  ardour,  or  raises  one  into  the 
sublime  spiritual  sphere  where  is  composed  the  joyous  music— not  under- 
stood by  all — which  acclaims  the  glory  of  existence,  or,  on  the  other  hand, 
drags  one  into  the  foul  pit  which  holds  only  fermenting  debris  of  mind  that 
nourishes  evil  germs  and  enzymes  of  crime  ;  joy  that  comes  of  labour  accom- 
plished and  rewarded  by  success ;  all  these  emotional  states,  associated  as 
they  are  with  the  changes  that  come  over  the  human  mind,  either  abruptly 
or  by  degrees,  only  come  about  through  the  continuous  dynamism  that  is  in 
consciousness,  a  dynamism  which  resembles  the  constant  motion  of  the  stars 
in  the  firmament. 

The  dynamism  and  the  movement  of  ideas  do  not  destroy  the  intimate 
texture  of  the  personality  which,  taking  its  tone  from  the  kinsesthesis, 
maintains  its  own  characteristic  individuality  in  the  constitution  of  which 
two  factors,  in  addition  to  those  already  mentioned,  play  a  part — viz. 
heredity  and  education  during  the  developmental  period.  • 

It  has  been  said  that  the  consciousness  of  each  individual  preserves  its 
own  particular  features  because  it  assimilates  the  external  world  with  its 
own  structures,  just  as  the  different  cells  of  the  organism  preserve  their 
original  morphological  and  chemical  characters,  notwithstanding  the  fact 
that  they  all  receive  the  elements  necessary  for  their  material  interchange 
from  the  same  circulating  lymph.  Molecules  are  for  cells  what  images  are 
for  consciousness.  The  images,  although  endowed  with  considerable  dynamic 
power,  pass  into  the  unconscious  after  they  have  traversed  the  illuminated 
field  of  consciousness.  "  The  unconscious "  is  the  great  bank  wherein  is 
deposited  all  the  capital,  be  it  large  or  be  it  small. 

The  unconscious  is  like  the  depth  of  the  sea  as  contrasted  with  the  surface, 
where  the  ship  of  life  sails  smoothly  on  or  is  tossed  amongst  the  waves ;  it 
is  like  the  bowels  of  the  earth  which  furnish  gold  and  coal  for  our  existence  ; 
or  like  the  immensity  of  space  in  which,  even  with  the  aid  of  the  telescope, 
our  eyes  can  see  only  a  comparatively  small  number  of  stars,  distant  millions 
upon  millions  of  miles  from  one  another,  yet  all  influencing  each  other  by 
physical  laws ;  it  is  like  the  power  and  wealth  of  a  country  prepared  by 
peaceful  spades  delving  deeply  into  the  earth  or  by  rasping  files  amidst  the 
feverish  activity  of  the  workshop.  What  appears  on  the  surface  of  mental 
life  is  but  a  small  part  of  all  that  exists.  The  illuminated  part  of  the  mind 
is  much  less  extensive  than  that  which  remains  wrapped  in  darkness.  The 
light  of  consciousness  emanates  from  the  inner  working  that  goes  on  in  the 
shades  of  the  subconscious,  just  as  electricity  is  developed  from  mysterious 
inner  processes  that  take  place  in  matter.  It  reminds  us  of  the  fact  that 
the  wealth  of  a  country  is  prepared  by  the  labours  of  thousands  of  arms  or  by 
the  unobtrusive  genius  of  a  few.  The  whole  mental  capital  is  preserved,  and 
to  a  very  large  extent  organised,  in  the  subconscious  just  as  the  external  world 
has  been  spiritualised  in  the  course  of  time  and  in  diverse  spaces.  The  work 
of  composition  of  the  mental  products  is  not  a  prerogative  that  is  vested  solely 
in  the  illuminated  field  of  consciousness,  rather  does  it  belong  to  the  dominions 


CONSCIOUSNESS  317 

of  the  subconscious.  Morselli1  writes  that,  apart  from  very  rare  and  ex- 
ceptional products  of  some  utility,  the  subconscious  gives  us  only  rejected 
products  which  we  are  constantly  casting  out  of  our  mental  life.  There  is 
truth  in  this  statement  if  we  apply  it  to  dreams,  somnambulism,  automatisms 
and  all  mental  diseases,  etc. — in  other  words,  to  the  subconscious  of  weak 
or  diseased  natures  and  to  distinctly  morbid  conditions  (trance,  hypnotic, 
hysterical,  etc.,  states).  That  apart,  however,  we  must  recognise  in  the 
illuminated  ego  a  high  evocative  and  selective  power,  in  obedience  to  which 
the  subconscious  furnishes  all  the  material  required  for  the  mental  construc- 
tions, no  matter  whether  these  be  mediocre,  ordinary,  or  brilliant  and 
original.  It  would  even  be  justifiable  to  hold  that  in  all  higher  living  creatures 
sleep  affects  this  selective,  regulative  and  creative  power  in  a  particular 
manner;  hence  it  is  that  organic,  tactile  and  auditory  stimuli  arouse  isolated, 
disconnected,  extravagant  representations  either  during  sleep  or  in  the 
course  of  disease — i.e.  when  the  light  of  waking  consciousness  is  spent.* 

1  Morselli.     "I  limit!  della  coscienza."     Riv.  di  filos.     1913. 

*  The  author  has  used  the  words  unconscious  and  subconscious  without  deliberate 
discrimination  in  meaning,  and  to  these  might  be  added  the  term  conconscious , 
introduced  by  Morton  Prince.  An  attempt  will  be  made  in  this  note  to  give  a  brief 
summary  of  the  prevailing  conception  of  to-day.  It  is  not  the  author's  intention  to 
treat  the  subject  in  extenso,  for  that  would  exceed  the  limits  he  has  put  upon  this 
work,  nor  does  what  follows  pretend  to  be  a  detailed  examination  or  criticism  of  the 
question  of  the  unconscious  and  the  subconscious.  The  unconscious  is  an  integral 
part  of  mind,  of  which  consciousness  is  the  illuminated  field  in  a  given  unit  of  time, 
and  it  is  not  quite  correct  to  say,  as  some  do,  that  it  is  completely  insusceptible  of 
analysis.  All  inquiries  dealing  with  hypnotism,  hysteria,  somnambulism,  and  dreams, 
represent  not  unfruitful  attempts  at  analysis.  All  the  works  of  Freud,1  apart  from 
exaggerations  and  certain  points  in  his  efflorescent  production  that  are  open  to 
criticism,  speak  of  the  possibility  of  analysis  of  the  unconscious  by  the  methods  of 
psycho-analysis,  which  have  aroused  keen  enthusiasm  in  some  countries.  (See, 
e.g.,  the  work  of  E.  Jones.2) 

The  unconscious  is  made  up  of  the  same  material,  is  constructed  on  the  same 
plan,  and  follows  the  same  laws  as  those  which  govern  the  evolution,  structure  and 
function  of  normal  mind,  and  it  emanates  from  the  same  anatomical  substratum. 
We  cannot  recognise  in  it  anything  of  the  abstract,  any  extra-physiological  power 
or  any  spontaneous  activity,  as  asserted  by  Dwelshauvers.3 

The  unconscious  is  that  part  of  nature  which  each  individual  has  succeeded  in 
spiritualising,  in  conjunction  with  all  the  mental  constructions  of  which  each 
individual  is  capable  and  with  the  memory-traces  of  all  the  reactions  (individual 
and  collective  experience)  determined  by  the  action  of  an  incalculable  number  of 
stimuli  which  have  excited  the  nervous  system  of  the  individual  and,  for  thousands 
of  years,  that  of  the  species. 

Mental  working,  which  resolves  itself  into  the  construction  of  mental  syntheses, 
is  set  in  action  by  external  stimuli  and  by  memory- traces,  recent  or  old,  which  reach 
the  illuminated  field  of  consciousness  ;  the  latter  detains  a  selected  theme  in  the 
focal  point,  and  thither  directs  a  flow  of  the  contents  of  the  subconscious.  The 
content  of  the  subconscious  is  utilised  by  consciousness  just  as  constructive  material 

1  Freud.     Studien  iiber   Hysteria.     2nd   edit.     1909.     Die   Traumdeutung.     3rd 
edit.     1912.     Zur  Psychopathologie  des  AlUagslebens.     4th  edit.     1914. 

2  E.  Jones.     Papers  on  Psycho -Analysis.     1913. 

3  Dwelshauvers.     L' Inconscient.     Paris,  191G. 


318  THE  MECHANISM  OF  THE  BRAIN 

The  appearance  of  higher  consciousness  coincides  with  the  integration 
of  preformed  psychic  complexes  by  the  addition  of  new-formed  images,  and 
with  conflict  between  the  dynamo-genetic  power  of  sensations  and  ideas 
and  the  inhibitory  power  exercised  by  other  image-records. 

The  development  of  inhibitory  power  in  the  psychic  domain  coincides 
with  the  appearance  of  the  frontal  lobes.  It  represents  in  the  psychic  field 
what  resistance  is  in  the  physiological  field.  We  know  from  the  researches 

is  used  by  the  artisan.  When  the  power  of  evocation  and  selection  becomes  sup- 
pressed along  with  that  special  form  of  will  which  serves  to  detain  in  consciousness 
an  argument  towards  which  the  work  of  the  subconscious  is  directed,  then  the 
subconscious  does  not  create  any  syntheses  of  real  intellectual  or  social  value. 

Experiments  in  hypnotism  such  as  carried  on  by  Epinas  and  Azam,  amongst  the 
first,  and  subsequently  by  Binet,  Janet,  Bernheim,  Bourgeois,  Sidis,  Morselli  and 
Belfiore,  have  all  demonstrated  the  poverty  of  the  product  of  the  unconscious, 
when  the  latter  is  not  controlled  and  directed  by  the  higher  consciousness.  Studies 
bearing  upon  hysteria — of  great  psychological  significance  because  hysteria  often 
presents  the  phenomenon  of  clouding  of  the  higher  consciousness,  which  permits 
the  content  of  the  unconscious  and  the  subconscious  to  enter  upon  the  scene  l ; 
inquiries  and  discussions  upon  spiritualism  of  which  the  most  complete  synthesis 
is  to  be  found  in  the  two  volumes  of  Morselli ;  the  detailed  investigation  of  the 
unconscious  by  the  methods  of  psycho-analysis,  introduced  by  Freud  and  Bleuler 
and  continued  with  success  by  Freud  and  Jung  who  have  written  extensively  on 
this  subject,  all  these  have  not  revealed  any  mental  construction  that  is  of  service 
to  life.  The  unconscious,  when  freed  from  the  evocative  and  constructive  influence 
of  the  higher  consciousness,  yields  nothing  but  trivialities.  Freud  has  found  in  the 
unconscious  nothing  more  than  the  traces  of  sensory  occurrences,  belonging  even  to 
infancy,  isolated  psychic  complexes  which  sometimes  have  acted  the  part  of  con- 
spirators even  from  the  period  of  childhood,  and  have  been  kept  in  submission  by 
the  consciousness,  which  exercises  the  right  of  censor.  He  has  found  none  of  those 
mental  constructions  which  take  a  place  in  the  intellectual  architecture  of  the 
human  subject,  or  which  represent  logical,  and  therefore  biophylactic,  reactions  in 
the  life  of  the  individual  or  the  community. 

The  artist  is  not  surprised  by  the  musical  motif  which  creates  enthusiasm  in  his 
auaience,  because  he  has  long  been  directing  and  dedicating  his  whole  intellect  and 
sentiment  to  the  creation  of  that  motif  and  the  whole  work  of  art,  which  is  often  the 
result  of  years  of  conscious  labour  and  of  will  to  select  and  detain  the  theme  in 
consciousness.  The  scientist  creates,  if  at  all,  only  after  long  and  Laborious  re- 
searches, during  which  his  mind  is  directed  to  the  solution  of  the  problem  that  has 
long  confronted  him,  unless  his  trained  perceptive  capacity  affords  him  occasion  to 
observe  some  new  fact  which  throws  sudden  light  upon  it.  That  is  the  function  of 
the  higher  consciousness.  Here  we  must  recognise  the  power  of  the  higher  con- 
sciousness in  directing  the  contents  of  the  unconscious  towards  the  illuminated 
field  where  the  theme  to  be  developed  is  detained,  the  subconscious  furnishing  the 
components  that  are  necessary  for  the  construction  of  the  intellectual  or  intellectuo- 
sentimental  syntheses.  There  seems  no  reason  to  doubt  the  existence  of  this  power. 
Mental  pathology  affords  good  proof  in  support  of  this  view.  The  man  who 
suffers  from  religious  paranoia  (paranoia  to-day  is  regarded  as  a  variety  of  dementia 
praecox)  for  months  on  end  directs  his  mind  towards  matters  connected  with  God 
and  religion,  and  if  at  length  he  observes  some  signs  or  movements  in  a  figure  of 
Christ  that  is  on  the  wall  of  his  room,  or  hears  it  speak  (hallucinations)  that  is  due 
to  the  evocative  and  expectant  attention  which  for  a  long  time  has  produced  an 


Bianchi.     "  Contributo  alia  conoscenza  dell'Isterismo."     Ann.  di  Nev.     1911. 


CONSCIOUSNESS  319 

of  physiologists,  especially  of  C.  Richet,1  that  the  time  taken  by  a  nervous 
current  to  reach  a  central  point  and  produce  a  reflex  is  in  proportion  to  the 
length  of  the  nerve  or  nerves  involved.  In  other  words,  the  length  of  time 
required  is  in  direct  ratio  to  the  distance  or  the  resistance,  and  this  corresponds 
with  the  universal  law  that  velocity  is  in  inverse  ratio  to  resistance.  To  the 
time  required  for  transmission  along  the  nerves  there  falls  to  be  added  a  latent 
time  occupied  in  the  centre  (in  the  cell  of  the  spinal  medulla,  in  the  case  of 

1  LOG.  cit. 


unusually  high  potential  in  the  cortical  and  auditory  fields,  and  so  has  resolved 
itself  into  the  corresponding  hallucinations.  Some  seven  years  ago  the  writer  had 
in  his  clinique  one  who  was  obsessed  by  the  memorising  of  words  which  she  was 
afraid  of  forgetting.  This  condition  caused  a  constant  anguish  during  which  she 
was  constantly  recalling  and  repeating  the  words  in  question.  After  years  of  this 
condition  the  patient  began  to  have  auditory  hallucinations  of  dissociated  words 
and  phrases.  Here,  too,  there  must  have  been  an  excessively  high  potential  in  the 
cerebral  acoustic  field  (and  a  corresponding  his  to -chemical  alteration)  giving  rise 
to  the  hallucination. 

I  have  grave  doubts  as  to  the  automatism  of  the  unconscious.  When  I  cannot 
remember  a  name  and  it  happens  that  this  comes  up  spontaneously  before  me  some 
time  afterwards,  perhaps  the  following  morning  on  awakening,  I  do  not  look  upon 
this  as  automatism,  but  rather  as  the  effect  of  the  direction  given  to  the  unconscious 
by  the  evocative  action  of  my  conscious  will.  I  do  not  mean  to  say  that  the  un- 
conscious is  totally  lacking  in  constructive  power,  but  it  seems  reasonable  to  suppose 
that  any  power  of  this  kind  is  directed  and  manifested  through  the  action  of  the 
conscious  will,  which  often  may  be  of  very  brief  duration.  The  whole  edifice 
erected  to  the  unconscious  from  investigations,  sometimes  very  commonplace,  of 
mediums  in  hypnotic  or  trance-states  impresses  me  as  being  a  falsification  of  what 
should  be  comprised  in  the  terms  unconscious  and  subconscious.  (I  use  these  two 
words  in  the  sense  of  degree  of  obscurity,  the  subconscious  being  regarded  as  the 
nearer  to  the  threshold  of  consciousness.) 

The  subconscious,  or  what  Sidis  x  calls  the  secondary  self,  would  not  be  a  thing 
entirely  by  itself.  It  is  a  form  of  mental  life  in  which  one  has  to  take  into  con- 
sideration the  co-ordination  of  many  series  of  moments-consciousness.  One  can 
understand  this  when  one  remembers  that  a  part,  perhaps  the  greatest  part,  of  the 
content  of  the  subconscious  has  at  one  time  passed  through  the  focal  field  of  con- 
sciousness, and  has  consequently  preserved  some  relationship  with  the  elements  of 
the  waking  consciousness,  no  matter  how  much  it  may  appear  to  be  completely 
isolated.  Further,  it  is  clear  that  without  wishing  it,  or  without  the  waking  con- 
sciousness being  aware  of  it,  some,  or  perhaps  many,  elements  of  the  subconscious 
are  attracted,  either  separately  or  as  complexes  (preformed  constellations),  from 
the  depths  of  the  unconscious  for  the  conscious  structure  of  mental  syntheses. 
Sometimes  these  elements,  drawn  from  the  unconscious,  are  recognised,  at  other 
times  they  are  not.  The  content  contributed  by  the  activity  of  the  senses,  and 
preserved  in  the  unconscious,  is  indestructible  ;  a  great  number  of  reactions  may 
be  traced  to  the  activity  of  impressions  received  during  childhood,  although  they 
may  have  remained  entirely  forgotten  and  incapable  of  reaching  the  focal  point 
of  consciousness,  except  under  particular  circumstances.  In  the  somnambulistic 
state  thoughts  and  memories  may  be  re-evoked  which  the  waking  consciousness 
has  never  been  able  to  call  up. 

In  the  state  of  maniacal  exaltation  a  number  of  memories  that  have  been 
entirely  obscured  by  time  may  come  to  the  surface.  Many  delusions  are  psychic 

1  Boris  Sidis.      The  Psychology  of  Suggestion.     1899. 


320  THE  MECHANISM  OF  THE  BRAIN 

spinal  reflexes),  for  the  metabolism  or  transformation  of  the  sensory  nervous 
waves  into  motor  or  centrifugal  waves.  To-day,  our  knowledge  of  the 
histology  of  the  nerve-cell  has  been  so  enlarged  by  the  researches  of  Golgi, 
Ramon  y  Cajal,  V.  Gehuchten,  Donaggio,  Lugaro,  Fragnito,  and  numerous 
other  investigators,  that  we  can  find  a  ready  explanation  of  the  long  loss  of 
time  in  the  nervous  centre  (group  of  cells).  We  can  understand  it  to  be  due 
to  the  enormous  resistance  offered  by  the  great  twisting  of  endocellular  and 

complexes  that  were  preformed  even  in  childhood,  and  kept  removed  from  the  field 
of  the  waking  consciousness  by  the  eliminating  power  of  the  latter  (censor),  because 
they  were  obviously  contrary  to  fact,  which  is  normally  perceived  as  such. 

Freud  maintains  that  the  whole  mental  life  represents  one  continuous  process. 
Apparent  discontinuity  is  only  an  illusion  due  to  the  fact  that  what  has  gone  before 
is  not  known.  According  to  him,  amnesia  of  this  kind  assumes  a  character  of  great 
importance,  and  is  due  in  some  cases  to  psychic  repression  resulting  from  education 
and  upbringing  in  early  age  or  from  the  hedonistic  attitude  in  life  and  the  influence 
of  new  sensory  and  intellectual  acquisitions  that  come  with  the  process  of  develop- 
ment. The  repressed  and  forgotten  images  do  not,  however,  always  lose  their 
dynamism. 

These  statements  cannot  all  be  confirmed  by  experimental  methods,  yet  one 
cannot  deny  that  the  facts  on  which  they  are  based  demonstrate  the  great  com- 
plexity and  the  great  wealth  of  the  subconscious,  as  well  as  the  manifold  relations 
that  subsist  between  the  subconscious  and  the  illuminated  consciousness. 

There  are  many  attitudes  in  the  life  of  each  individual  that  have  their  origin  in 
the  content  of  the  unconscious  without  the  higher  consciousness  being  aware  of  it. 
The  writer  can  take  his  own  case  as  an  example.  He  was  educated  in  a  naturalistic 
environment  by  his  father,  who  was  a  chemist  and  botanist.  When  he  had  com- 
pleted his  course  at  the  Lyceum  he  was  commanded  by  his  father  to  enrol  in  the 
Faculty  of  Jurisprudence.  The  writer  objected,  and  was  quite  rebellious  to  the 
wish  of  his  father,  whom  he  really  adored.  Never  before  had  he  opposed  his  desire, 
but  on  that  occasion  he  felt  an  irresistible  attraction  for  the  study  of  Natural  Science 
and  of  Medicine  which  caused  him  many  heart  burnings  owing  to  the  strained 
relations  with  his  father,  who  was  a  severe  man  and  of  strong  will.  The  writer 
afterwards  came  to  explain  the  reason  of  his  choice  as  being  due  to  the  information 
about  nature  and  naturalistic  phenomena  which  he  was  constantly  deriving  from  his 
father,  and  to  the  satisfaction  he  experienced  in  childhood  from  the  little  that  he  knew 
of  nature — a  fact  of  which  he  was  quite  unconscious  when  he  chose  his  path  in  life. 

Dreams  undoubtedly  offer  a  rich  material  for  the  study  of  the  problem  of  the 
subconscious.  Their  origin  is  very  complex  and  very  varied  in  nature.  One  can 
give  heed  to  the  doctrine  formulated  by  Freud  concerning  the  origin  of  dreams 
which,  in  the  case  of  children,  he  connects  with  a  latent  content,  which  would  give 
rise  to  the  imaginary  satisfaction  of  a  repressed  wish.  This  is  specially  character- 
istic of  the  dreams  of  children.  The  wish  repressed  by  the  censuring  consciousness 
cannot  penetrate  consciousness,  but,  during  sleep,  when  the  power  of  the  waking 
consciousness  is  suppressed,  the  latent  content  would  reveal  itself.  According  to 
Freud,  the  presence  of  the  repressed  thought  or  wish  finds  confirmation  in  the  fact 
that  a  reasoned  and  conscious  wish  is  inadequate  to  produce  a  dream  unless  it  be 
associated  with  another,  repressed  and  unconscious,  wish  which  would  be  the  real 
instigator  of  the  dream.  If  this  is  true  of  some  dreams,  there  are  yet  many  other 
causes  of  dreams,  amongst  them  the  internal  and  external  corporeal  impressions 
which,  through  unconscious  association,  provoke  a  number  of  dissociated  and 
strange  imaginary  complexes  (dreams),  owing  to  the  fact  that  sleep  takes  over  in  its 
own  special  way  the  directive  and  selective  power  of  consciousness.  (A  more  complete 
study  of  this  subject  will  be  found  in  the  work  of  S.  De  Sanctis.  "I.  Sogni."  1899. ) 


CONSCIOUSNESS  321 

extra-  or  peri-cellular  neuro-fibrils  in  a  more  or  less  extensive  field  of  cells 
before  the  current  assumes  its  centrifugal  character  in  the  motor  paths. 

As  we  cannot  imagine  inhibition  to  be  a  watchful,  regulative  power  which 
is  exercised  from  a  distance,  and  much  less  think  of  it  as  an  occult  force,  it 
is  necessary  to  trace  the  phenomenon  to  its  objective  physical  mechanism. 
There  is  no  other  way  of  understanding  it. 

It  will  help  us  to  comprehend  the  phenomenon  if  we  start  out  with  the 

The  subconscious  is  revealed  also  by  many  acts  performed  by  the  generality  of 
men ;  these,  though  apparently  void  of  any  psychic  significance,  are  yet  found 
through  psycho-analysis  to  be  determined  by  unconscious  motives. 

The  genesis  of  many  slips  of  the  tongue  (lapsus  linguce)  which  even  those  well 
accustomed  to  speaking  sometimes  make,  and  slips  of  the  pen  (lapsus  calami) 
may  be  traced  to  the  unconscious.  They  are  certainly  not  always  due  to 
inattention. 

In  still  other  cases  we  find  evidence  of  the  action  of  memory-traces  preserved  in 
the  unconscious.  For  example,  if  we  invite  a  child  to  mention  a  number,  that 
chosen  is  often  the  vague  memory  of  the  same  or  an  analogous  number  that  has 
fallen  into  oblivion.  The  case  mentioned  by  Adler  ("Drei  Psychoanalysen  von 
Zahleneinf  alien,"  etc.  Psychiat.  NeuroL  Woch.  1905)  is  very  suggestive  in  this 
regard. 

We  forget  many  things  the  memory  of  which  is  painful.  Man  assumes  an 
attitude  of  defence  against  painful  memories.  We  are  constantly  finding  ourselves 
confronted  by  the  hedonistic  law  of  life  ("Zur  Psychologic  des  Vergessen,"  etc. 
Archiv.  f.  Kriminal-Anthropologie.  1905). 

In  the  case  of  lapsus  we  can  trace  the  influence  of  another  train  of  ideas  which 
has  not  crossed  the  limits  of  consciousness.  Some  of  these  errors  are  evidently  of 
a  mixed  nature.  The  author  is  acquainted  with  a  man  who  often  makes  slips  in 
writing  in  that  he  interposes  in  the  structure  of  a  word  a  syllable  or  letter  that 
belongs  to  the  word  that  follows.  In  this  case  the  phenomenon  has  a  double  origin. 
There  is  the  element  of  inattention,  but  there  is  also  at  work  the  influence  of  a 
preformed  representation  which  comes  forward  of  its  own  account.  The  latter 
phenomenon  finds  its  explanation  in  the  influence  exercised  by  thoughts,  images  or 
wishes  on  the  motor  determinism,  independently  of  the  waking  consciousness. 

Thus,  there  exists  a  consciousness  or  vigilant  self  and  a  sub-vigilant  consciousness 
(Boris  Sid  is  x).  A  pen  put  between  the  anaesthetic  fingers  of  a  hysterical  woman 
determines  adapted  movements  of  writing.  If  the  outline  of  a  letter  be  traced  on 
the  back  of  an  anaesthetic  finger  of  a  hysterical  patient,  the  letter  may  be  repro- 
duced by  the  hand  making  appropriate  movements.  A  patient  suffering  from 
hysterical  blindness  may  see  an  object  of  which  her  waking  consciousness  knows 
nothing  (experiment  of  Binet2).  The  return  to  memory  of  things  that  were  com- 
pletely forgotten  or  were  never  actually  apprehended  by  the  waking  consciousness 
because  they  affected  only  the  senses,  and  did  not  bring  voluntary  attention  into 
play,  and  the  reawakened  memory  of  things  seen  in  infancy,  accompanied  by 
recognition  of  places  and  circumstances,  are  facts  which  reveal  the  existence  of 
psychic  processes  which  take  place  without  us  being  fully  conscious  of  them. 

We  are  bound  to  agree  that  in  the  obscure  domain  of  the  mind  there  may  be 
buried  or  concealed  many  memory-traces  which  never  come  into  the  illuminated 
field  of  consciousness,  and  that  many  reactions  take  place  quite  outside  that  field. 
Whether  we  have  to  deal  with  a  secondary  consciousness  or  whether,  as  the  writer 


1  Boris    Sidis.     The    Psychology    of    Suggestion.     New    York,    1899.     Psycho- 
pathological  Researches  in  Mental  Dissociation.     1902. 

2  Binet.     "  Sur  les  alterations  de  la  conscience.     Rev.  Philos.     1884. 


X 


322  THE  MECHANISM  OF  THE  BKAIN 

obvious  fact  that  all  the  nervous  organs  together  constitute  a  circulatory 
system  for  nerve-waves,  which  is  much  more  complicated  than  that  con- 
cerned with  the  circulation  of  the  blood.  No  observer  can  have  failed  to  be 
impressed  by  the  fact  that  the  circulation  of  the  nerve-waves  is  regulated 
by  the  same  laws  as  those  pertaining  to  liquids  in  enclosed  tubes  and  to 
the  circulation  of  electric  currents  in  conducting  wires.  This  hypothesis  has 
been  confirmed  by  psycho-physical  researches.  We  know  that  in  the  process 

thinks,  these  facts  deserve  a  different  interpretation,  this  is  not  the  place  to  discuss. 
All  that  is  aimed  at  in  this  brief  summary  of  the  doctrine  of  consciousness  is  to 
establish  the  conception  that  what  we  call  the  waking  or  vigilant  consciousness  is 
only  a  part  of  our  mind,  that  another  part  remains  in  the  penumbra,  and  still  another 
and  larger  part  in  completed  arkness  ;  but  it  is  all  one  organisation,  which  manifests 
itself  through  the  same  anatomical  substratum  and  by  the  same  dynamism. 

If  any  further  proof  were  required  to  convince  us  that  the  whole  corpus  mensis 
is  one  single  function,  notwithstanding  the  distinction  into  an  illuminated  field 
(waking  consciousness)  and  a  more  or  less  obscured  field  (the  unconscious  and  sub- 
conscious), it  is  furnished  by  the  examination  of  the  phenomenon  of  hallucination. 
The  author  must  not  here  dwell  upon  the  internal  mechanism  of  hallucinations  or 
upon  the  different  interpretations  put  forward  by  Tamburini  and  Tanzi x  and  others, 
but  it  is  opportune  to  mention  Ballet's  view  inasmuch  as  it  touches  the  relations 
between  hallucination  and  personality. 

Ballet 2  holds  that  hallucination  is  the  effect  of  dis aggregation  or  dissociation  of 
the  personality.  An  unprejudiced  examination  of  the  facts  and  their  mode  of 
succession  shows  that  hallucination  is  the  effect  of  a  morbid  state  of  the  sensory 
fields,  whose  abnormal  product,  the  hallucination,  surprises  the  consciousness  and 
dissociates  or  decomposes  the  personality.  The  higher  consciousness  elaborates 
the  material  prepared  and  furnished  by  the  sensory  field.  It  is  different  when  we 
come  to  deal  with  mediumistic  states  and  induced  somnambulism.  In  this  case  the 
waking  consciousness  is  deposed  whilst  the  sensory  function  is  exalted  as  the  result 
of  the  hypnotic  or  spiritualistic  practices.  The  somnambulistic  and  trance  phases, 
as  practised  by  spiritualists  upon  the  medium,  are  always  accompanied  by  ob- 
scuration of  the  higher  consciousness  (superliminal  consciousness  of  Myers),  a  kind 
of  sleep,  and  at  the  same  time  by  exaltation  of  the  sensory  field. 

When  the  author  occupied  himself  with  hypnotism  he  was  always  able  to 
observe  these  two  facts.  The  slightest  stimulus  produces  a  brief  movement  of 
thought,  and  a  reaction,  or  group  of  reactions,  generally  isolated.  More  complex 
actions  and  a  wider  movement  of  thought  require  to  be  suggested  to  the  hypnotised 
person.  There  is  no  trace  of  any  power  which  evokes  and  directs  the  intellectual 
function ;  no  power  which  utilises  the  capital  accumulated  through  the  working  of 
the  brain  on  objective  and  subjective  reality,  and  now  lying  dormant  in  the 
cerebral  archives.  On  the  other  hand,  it  is  very  easy  with  the  slightest  stimuli, 
or  by  command,  or  simple  suggestion,  to  awaken  images  or  groups  of  images  and 
even  hallucinations. 

The  phenomenon  of  duplication  of  the  consciousness  or  of  the  personality,  as 
exemplified  in  the  cases  recorded  by  Camuset,  Morton  Prince,  by  the  author,3  and 
several  others,  is  more  complex.  What  significance  is  to  be  attached  in  these  cases 
to  the  behaviour  of  the  secondary  (subliminal)  self  as  manifested  in  logical  actions, 


1  Trattato  di  Psichiatra.     Tanzi  and  Lugaro.     Malattie  Mentali.     2nd  edit. 

2  Ballet    et    Mallet.      "  Hallucinations    et    dissociations    de    la    personnalite." 
L' Encephale.     1913.      Ballet.     "  La    Psychose    hallucinatoire    chronique    et    dis- 
sociation de  la  personnalite."     L'Encephale.     1913. 

8  Bianchi,     Trattato  di  PsicUatria.     2nd  edit.     1915. 


CONSCIOUSNESS  323 

of  evolution  of  the  nervous  system  new  organs  are  developed  and  close 
anatomical  relations  are  established  between  these  and  the  pre-existing 
organs — in  other  words,  the  field  of  circulation  of  the  nerve-waves  becomes 
more  extensive,  and  consequently  a  higher  potential  is  required  in  order  to 
overcome  the  increased  resistances  of  the  new  paths,  proportionately  to  the 
extent  of  the  new  field. 

One  can  readily  understand  that  if,  for  any  reason  whatsoever  (artificial 
irritation,  morbid  processes,  excessive  functioning,  etc.),  one  area  receives  an 
addition  to  its  nervous  charge,  this  is  to  the  detriment  of  the  other  areas, 
in  which  the  charge  will  be  diminished  by  just  so  much  as  it  is  increased  in 
the  excited  part  of  the  nervous  system.  The  former  are  inhibited  through  the 
hyper-functioning  of  the  latter.  In  accordance  with  this  view,  any  central 
nervous  organ  may  inhibit  or  be  itself  inhibited  as  circumstances  occur. 

We  get  disturbance  of  the  equilibrium  of  the  nervous  circulation  and 
increase  of  the  charge  in  certain  parts  of  the  nervous  system,  when  any  field 
of  propagation  in  the  brain  becomes  suppressed  or  cut  off  from  the  other 
organs,  owing  to  interruption  of  the  paths  of  communication  between  them. 

Given  the  free  circulation  of  the  nervous  currents  through  all  the  central 
areas  of  the  system  which  are  connected  with  the  peripheral  areas  by  means 
of  centripetal  paths  (the  conducting  wires),  we  get  a  greater  charge  of  nervous 
force  in  the  lower  cerebral  organs  when  these  are  separated  from  the  higher, 
and  this  gives  rise  in  turn  to  an  increased  excitability  which  resolves  itself 
into  augmented  reflex  action.  Exaggeration  of  the  reflexes  and  diminution 
of  the  time  of  reaction  are  due  to  the  simple  physical  facts  that  the  field  of 
propagation  is  diminished  and  that  consequently  the  nerve-waves  become 
concentrated  in  a  more  restricted  field  of  distribution.  The  tonic  contraction 
of  certain  groups  of  muscles  (on  the  opposite  side)  that  follows  immediately 
on  removal  of  one  cerebral  hemisphere  or  of  both  cerebral  hemispheres 
(contractions  on  both  sides),  such  as  observed  by  Sherrington,1  is  likewise 
an  effect  of  suppression  of  an  extensive  field  of  propagation  of  the  nerve- 
waves  which  are  constantly  being  aroused  by  external  stimuli  and  trans- 
mitted in  a  centripetal  direction.  These,  finding  their  paths  obstructed, 
overrun  the  lower  centres,  augmenting  their  potential,  which,  in  turn, 
becomes  discharged  along  the  motor  paths,  thus  giving  rise  to  tonic  con- 
traction of  the  muscles  in  the  first  instance  and  to  exaggeration  of  the  reflexes 
in  the  next.  We  know  that  in  the  cerebral  mantle  there  exist  distinct 
areas  for  groups  of  muscles  which  contract,  and  for  their  antagonists  which 
relax.  We  also  know  that  on  exciting  the  area  belonging  to  the  first  group 

accompanied  by  a  certain  movement  in  thought  but  with  unusual  affective  orienta- 
tion, and  how  there  arises,  and  what  value  one  is  to  assign  to,  the  symbolic 
diaphragm  of  Myers,2  are  fields  of  discussion  which  lie  beyond  the  limits  assigned 
to  this  volume. 


1  Sherrington.     "  Decerebrate  Rigidity."     Journ.   of  Physiol.     Cambridge  and 
London, 1898. 

2  Myers.     Human  Personality  and  its  Survival  to  Bodily  Death.     1902. 


324  THE  MECHANISM  OF  THE  BRAIN 

the  corresponding  muscles  enter  into  a  state  of  contraction,  whilst  at  the 
same  time  their  antagonists  become  relaxed.  In  the  writer's  view  this  is 
due  to  the  fact  that  the  potential  in  the  area  belonging  to  the  antagonistic 
group  of  muscles  becomes  diminished  during  excitation  of  the  other  area. 

That  is  the  most  likely  interpretation  that  can  be  offered  of  the  experi- 
ments of  Sherrington,  of  Herring  and  Sherrington,1  Topolanski,2  Libertini, 
Oddi,  and  Fano.3  The  last-named  physiologist  found  that  removal  of  the 
whole  frontal  lobe,  including  the  sigmoid  gyrus,  led  to  shortening  of  the 
reaction- time,  whilst  electric  stimulation  of  the  frontal  lobes  lengthened  it. 

This  lengthening  of  the  time  of  reaction  we  call  inhibition,  but  it  is  clear 
that  it  is  nothing  else  than  the  physiological  effect  of  an  experimental  physical 
condition — viz.  an  increase  of  the  quantity  of  nervous  waves  in  the  frontal 
lobes  owing  to  the  influx  that  takes  place  under  the  action  of  the  electric 
stimulus,  and  a  consequent  diminution  of  the  charge  of  nervous  force  in  the 
remaining  parts  of  the  cerebro-spinal  axis.  So  far  as  this  question  is  con- 
cerned, it  is  very  doubtful  what  value  is  to  be  attached  to  researches  made 
with  the  object  of  demonstrating  that  the  frontal  lobes  are  a  centre  of  in- 
hibition. All  points  of  the  cerebral  mantle  may  either  be  inhibitory  organs 
or  may  themselves  be  inhibited,  according  as  they  are  stimulated  or  as  other 
neighbouring  or  distant  areas  with  which  they  have  functional  relations  are 
stimulated. 

The  inhibitory  power  is  greater  or  less  according  to  the  degree  of  functional 
dignity  of  the  cerebral  area  concerned  and,  one  might  add,  according  to  the 
number  of  associative  relations  which  it  has  with  other  parts  of  the  central 
nervous  system.  As  the  frontal  lobe  does  not  send  any  fibres  directly  to  the 
spinal  medulla,  nor  receive  any  from  it  (vide  Chapter  VII.),  its  inhibitory 
power  over  the  spinal  medulla  can  only  be  exercised  through  an  indirect  path. 
It  is  sufficient  to  see  the  number  of  associative  fibres  that  run  between  the 
frontal  lobe  and  the  Rolandic  area  to  be  convinced,  without  stretch  of 
imagination,  that  any  stimulation  of  the  frontal  lobes  must  induce  such  a 
flow  of  nerve-waves,  especially  from  the  Rolandic  area,  that  the  nervous 
charge  becomes  lowered  in  all  the  rest  of  the  cerebro-spinal  axis  which  there- 
fore finds  itself  in  a  hypo -functional  condition.  Vice  versa  when  the  frontal 
lobes  are  removed,  the  nerve-waves  which  were  destined  to  pass  to  the 
frontal  lobes,  whose  field  is  now  destroyed  or  obstructed,  accumulate  in  other 
centres  and  this  explains  their  greater  excitability. 

We  find  in  Loeb's  work4  a  psycho-physical  conception  of  inhibition 
similar  to  that  here  expressed.  Most  physiologists  who  have  investigated 
this  phenomenon  seem  to  have  confined  their  attentions  to  the  effects  of 
excitement  or  destruction  of  certain  segments  of  the  central  nervous  system 
(see  Chapter  IV.).  The  view  which  the  writer  here  puts  forward  is  one 

1  Herring  and   Sherrington.      Arch.  f.   die   Gesels.    Physiologic,   and   Journ.   of 
Physiology.     1898. 

2  Topolanski.     Arch.  f.  Ophtalm.     Leipzig,  1898. 

3  Fano.     Archives  italiennes  de  Biologie.    1895.     (See  also  Chapter  II.) 

4  Loeb.     Loc.  cit. 


CONSCIOUSNESS  325 

which  he  clearly  expressed  twenty-five   years  ago  in  an  article  on  the 
symptomatology  of  gait.1    The  following  is  a  quotation  from  that  article : — 

"  The  interpretation  of  this  inhibitory  action  or  action  of  arrest  is  one 
of  the  most  difficult  things  in  physiology.     To  appreciate  it  we  must  start 
from  a  datum  of  common  observation.     Each  person,  by  innate  organisa- 
tion, possesses  an  exponent  of  nervous  force  that  depends  upon  the  nutritive 
activities  of  his  nervous  centres,  upon  individual  capacity  to  assimilate  and 
dissimilate,  and  upon  the  particular  congenital  and  hereditary  molecular 
disposition.      The  quid  which  we  call    nervous    force,   in    making    itself 
manifest   in   different   individuals,   displays   particular   qualities   that   are 
inherently  dependent  upon  the  structural  details  of,  and  the  central  and 
peripheral  relations  between,  the  organs  in  which  it  is  developed,  in  which 
it  is  modified   and  from  which  it  emanates.     It  thus   presents  different 
characters  in  the  form  of  various  sensations,  emotions  and  sentiments,  as 
well  as  consciousness,  perceptive  attention,  desire,  will,  movement,  etc.   The 
various  faculties  draw  from  a  common  source,  are  modifications  of  one  and 
the  same  force,  and  they  equalise  and  compensate  one  another.     If,  as  the 
result  of  particular  circumstances  special  to  its  own  organ,  one  faculty  acquires 
greater  development  than  the  others,  under  equal  conditions,  the  latter 
become  depressed  by  just  so  much  as  the  former  is  exalted.     This  appears 
to  be  a  general  law  and  it  is  not  belied  by  the  behaviour  of  any  of  the  modes 
of  extrinsication  of  nervous  properties,  from  the  lowest  to  the  highest.     If 
we  augment  the  sensibility  of  a  particular  area  of  skin  on  one  side  by  the  use 
of  any  sesthesiogenic  body,  the  sensibility  of  the  homonymous  area  of  the 
other  side  is  correspondingly  reduced.     Vice  versa,  if  we  lull  the  sensibility 
of  any  given  area  of  the  body  by  the  use  of  a  magnetic  pole,  the  sensibility 
of  the  homonymous  area  of  the  other  side  is  correspondingly  increased.     All 
strong  sensations  of  pleasure  or  of  pain  arrest  or  retard  other  extrinsications 
of  nervous  energy,  because  every  strong  sensation  represents  an  excessive 
consumption  of  nervous  energy,  to  the  detriment  of  other  functions.     If  an 
individual  engaged  in  deep  meditation  voluntarily  determines  to  make  an 
energetic  movement,  or  rather  an  effort,  a  certain  proportion  of  the  reflective 
intensity  is  lost  in  that  movement.     A  man  who  wishes  and  ardently  desires 
anything  does  not  allow  himself  to  be  much  impressed  by  external  or  internal 
circumstances ;  that  is  another  way  of  saying  that  organs  which  should  be 
receptors  and  elaborators  of  new  impressions  from  without  are  not  equal  to 
their  task,  because  their  nervous  force  has   been  reflected  upon  another 
territory  and  has  left  them  thereby  weaker.     If,  whilst  one  is  suffering  from 
a  severe  pain,  another  pain  is  induced,  the  intensity  of  the  first  diminishes 
proportionately  to  the  intensity  of  the  second.     The  reflexes  which  occur, 
sometimes  in  an  intense  form,  in  consequence  of  pain  are  no  exception  to 
the  rule ;  all  of  them,  from  the  simple,  rapid  movement  of  the  hand  to  the 
site  of  the  pain  (somatic  pain)  up  to  raptus  melancholicus  of  the  agitated 

1  Bianchi.     "  Le   andature."     Giorn.   Internaz.   di  scienze  mediche.     1885 ;    also 
Semiotica  delle  malattie  nervose.     Milan,  1879. 


326  THE  MECHANISM  OF  THE  BEAIN 

melancholiac,  are  only  realised  at  the  expense  of  some  other  variety  and  mode 
of  extrinsication  of  nervous  energy  ;  indeed  this  may  go  so  far  as  to  result  in 
loss  of  consciousness.  There  is  no  end  to  the  examples  that  might  be  quoted 
in  support  of  this  fact.  Good  nervous  organisation  consists  not  only  in  the 
possession  of  a  given  quantity  of  nervous  force  which  must  not  fall  below 
certain  limits,  but  also  in  the  regular  augmentation  of  that  energy  under  the 
influence  of  education  and  other  agents  which  operate  upon  us,  in  its  due  and 
proper  distribution,  permitting  functional  harmony  between  the  various 
organs  of  the  nervous  system,  and  in  its  relative  steadiness  or  not  too  great 
mobility  so  that  it  should  be  capable  of  being  deflected  now  into  one  field, 
now  into  another  of  different  functional  dignity,  in  response  to  more  or  less 
adequate  stimuli. 

"  These  last  two  conditions  in  psychology  form  the  basis  of  character 
and  the  tone  of  mind.  If  for  any  reason  whatsoever  the  nervous  energy  of 
which  we  have  been  talking  should  discharge  itself  through  any  path  with 
unusual  rapidity,  other  conditions  being  equal,  this  will  take  place  at  the 
expense  of  consciousness  and  retentivity.  W  e  find  examples  of  this  in  the 
movements  of  the  maniac  and  in  the  volatile,  irresponsible  conduct  of  some 
people.  Psychology  follows  the  laws  of  physics. 

"  It  is  well  recognised  that,  of  all  the  functions  of  the  nervous  system,  pain 
and  attention  are  those  which  have  most  effect  upon  the  consciousness,  con- 
suming the  greatest  amount  of  nervous  force  and  depriving  other  organs  of 
their  fair  share  with  the  result  that  they  remain  in  a  condition  of  hypo- 
activity.  Apart  from  the  object  which  claims  their  attention  or  causes  their 
pain  or  grief,  the  sufferers  pay  little  or  no  heed  to  the  attractions  of  the 
external  world  and  do  not  react  thereto  or  only  feebly,  if  at  all.  This  explains 
why  those  who  suffer  from  pain  or  grief  remain  motionless,  or  walk  with  slow 
and  difficult  pace.  On  the  other  hand  pleasure,  regarded  from  the  psycho- 
physical  point  of  view,  consists  essentially  in  facility  of  resolution  of  the 
psychic  tensions.  We  cannot  imagine  pleasure  where  there  is  an  obstacle. 
This  ready  flowing  of  the  nervous  currents  brings  it  about  that  the  pleasur- 
able sensation  impresses  itself  less  upon  the  consciousness  than  would  other- 
wise be  the  case,  and  is  readily  deflected  into  all  the  outgoing  paths,  in  the 
form  of  a  centrifugal  current.  As  a  rule,  the  man  who  has  a  happy  disposition 
of  mind,  moves  about  with  lightness,  facility  and  rapidity.  The  dispersal 
of  nervous  energy  along  the  centrifugal  paths  occurs  at  the  expense  of  the 
provinces  of  consciousness  and  reflection,  and  in  all  degrees  from  normal 
conditions  to  the  most  violent  excitement  of  the  maniac/' 

The  above  statement  reaffirms  in  a  different  manner  the  well-founded 
view  that  one  cannot  conceive  of  a  conscious  phenomenon  arising  from 
stimulation  of  a  very  small  number  of  cortical  nerve-cells.  Any  conscious 
phenomenon  presupposes  the  propagation  of  an  external  or  internal  stimulus 
to  a  large  number  of  nerve-cells  in  the  mantle.  Tanzi  and  Lugaro  1  express  a 
similar  view. 

1  Tanzi  and  Lugaro.     Malattie  mentali.     2nd  edit.     1914. 


CONSCIOUSNESS  327 

The  fact  that  the  cell- structure  of  the  nervous  system  is  incapable,  so  far 
as  we  know,  of  modification  does  not  stand  in  the  way  of  acceptance  of  the 
view  expressed,  because  that  power  of  starting,  directing,  evoking  and 
selecting  the  nervous  currents  which  we  attribute  to  the  frontal  lobes  would 
appear  to  be  possessed  also,  in  a  minor  degree,  by  all  the  cell-groups  of  the 
mantle,  the  so-called  plejadi  isodinamiche  of  Cajal. 

Human  actions  are  the  resultant  of  impulsions  and  inhibitions.  The 
inhibitory  power  is  more  active  where,  other  conditions  being  equal,  the 
mental  field  is  more  extensive  and  the  capital  of  cognitions  more  conspicuous, 
or,  in  other  words,  when  a  larger  number  of  isodynamic  pleiads  take  part 
in  the  mental  processes.  Inhibition  is  less  active  where  the  mental  field  is 
more  restricted  and  consciousness  more  obstructed. 

In  mental  life,  then,  the  phenomena  of  inhibition  may  be  regarded  as 
regulated  by  physical  laws  analogous  to  those  which  regulate  the  flow  of 
liquids  in  closed  tubes  or  of  electric  currents  in  conducting  wires. 

An  internal  or  external  stimulus  A  on  reaching  consciousness  provokes 
an  intuition  of  movement,  accompanied  by  a  charge  of  potential  for  the  move- 
ment X.  If  at  the  same  moment  or  immediately  afterwards  another  stimulus 
B  reaches  consciousness,  one  of  two  things  occurs :  the  stimulus  B  and  the 
mnemonic  residuum  rearoused  (from  past  experience)  may  be  convergent 
and  harmonious  with  A,  which  in  this  case  becomes  reinforced  by  the  deter- 
minative power  of  B,  and  we  get  X=A-fB.  This  summation  of  potential 
reinforces  the  effort  or  accelerates  the  movement  initiated  by  A,  or  it  trans- 
forms the  simple  tendency  or  intuition  towards  movement,  which  was  induced 
by  this  stimulus  A  alone,  into  actual  movement.  On  the  other  hand,  what 
may  happen  is  this  :  the  second  stimulus  B  may  be  of  a  contrasting  nature 
and  opposed  to  A.  In  this  case  it  is  evident  that  the  movement  X  will 
become  X=A— B.  According  to  the  strength  of  B,  we  will  have  a  pro- 
portionate decrease  of  the  potential  or  charge  that  is  necessary  for  realisation 
of  the  initial  movement  provoked  by  A.  This  dynamic  situation  is  what  is 
called  inhibition.  If  B,  which  is  in  contrast  with  A,  is  very  strong,  A  loses 
all  its  determinative  efficacy  because  of  the  presence  of  another  nervous 
charge  and  a  different,  sometimes  opposite,  tendency  towards  movement, 
so  that  the  first  movement  will  not  now  take  place.  It  may  even  be  sub- 
stituted by  another  in  a  totally  opposite  direction  and  with  a  different  objec- 
tive. When  we  speak  of  stimuli  in  the  mental  field  we  mean  actual  percep- 
tions or  mnemonic  traces  of  past  experiences  and  the  psychic  complexes 
derived  from  these,  with  their  corresponding  emotional  conditions  (more 
or  less  ex  tensive  mental  or  associative  fields  that  are  capable  of  being  utilised 
and  of  being  brought  into  action  in  a  given  unit  of  time) .  Thus  we  get  arrested 
or  inhibited  motor  intuitions. 

Certain  delicate  experiments  have  been  made  which  lend  support  to  this 
conception.  Pavlov  carried  out  a  number  of  experiments  which  prove  that 
the  salivary  secretion  is  very  sensitive  to  the  action  of  external  stimuli  and 
that  these  act  and  counteract,  excite  and  inhibit,  according  to  circumstances. 


328  THE  MECHANISM  OF  THE  BRAIN 

In  the  higher  mammals  and  in  man  the  various  actions  become  com- 
plicated with  the  memory  of  previous  actions  and  reactions,  and  with  all  the 
reserves  of  experience  in  the  life  of  each  individual  and  of  the  social  group. 
The  nervous  system  is  not  a  mere  reflector  of  external  agents ;  it  registers, 
conserves,  and  reproduces  the  images  of  external  stimuli ;  it  combines  them 
together  and  acts  as  a  multiplier,  a  storehouse  and  an  accumulator  of  energies ; 
it  is  at  the  same  time  capable  of  new  forms  of  reaction  under  the  influence  of 
educative  processes  (Pavlov,  Cathcart).1 

Wassiliew  and  Michtovte  are  mentioned  by  Bohn 2  as  having  demon- 
strated the  fact  that  any  excitation  whatsoever  from  the  external  world,  or 
even  anything  that  is  in  itself  indifferent,  may  become  an  inhibiting  agent, 
arresting  some  previously  existing  action.  This  inhibiting  action  is  what 
Pavlov  would  call  a  conditional  restraint.  Orbelli,  again,  clearly  establishes 
the  fact  that  the  two  fundamental  elements  in  the  physiology  of  the  nervous 
system  which  explain  the  great  complexity  of  its  functions  in  general,  in- 
cluding psychic  activity,  are  excitation  and  inhibition.  With  regard  to 
inhibition  Bohn  expresses  a  view  similar  to  that  put  forward  by  the  writer 
in  1885  and  again,  in  more  distinct  terms,  in  1910  during  the  Congress  of 
Scientists  in  Naples.  In  1911,  we  find  Bohn  writing  as  follows  : — "  It  now 
appears  that  the  higher  psychic  activities  may  be  traced  to  strictly  deter- 
mined laws."  One  must  also  take  into  account  all  that  we  inherit  from 
generations  of  ancestors.  "  We  are  the  slaves  of  our  dead,"  wrote  Comte. 

If  with  this  scheme  in  front  of  our  minds  we  can  imagine,  on  the  one 
hand,  a  constant  movement  of  ideas,  and  on  the  other  hand,  a  continuous 
flow  of  diverse  internal  stimuli,  desires  and  sentiments  which  are  unceasingly 
invading  the  consciousness,  and  the  incessant  action  of  an  infinite  number  of 
external  stimuli  which  are  ever  impinging  upon  our  nerves,  and  the  various 
products  which  are  formed  from  these  in  the  busy  workshops  of  the  sensory 
(and  emotional)  centres,  then  we  will  form  some  idea  of  the  great  complexity 
of  the  mechanism  of  conduct  both  in  individuals  and  in  social  groups,  whose 
actions  are  always  the  resultant  of  impulsive  and  contending  forces — that  is 
to  say  of  judgments,  desires,  motor  impulses  and  inhibitions.  If  we  have 
recourse  to  introspection  and  examine  our  consciousness,  retracing  our 
history  (and  that  of  our  acquaintances),  we  feel  that  every  day,  every  hour 
perhaps,  our  consciousness  has  been  an  open  arena  for  combats  of  contending 
elements  that  surround  us  on  every  side,  elements  that  are  ever  exciting 
desires  and  aspirations,  and  tending  to  become  part  and  parcel  of  ourselves, 
entering  into  combination  with  the  other  intrinsic  components  of  our  minds. 
The  latter  may  offer  resistance  if  the  new-comers  are  opposed  to  social  interests, 
for  they  are  the  alert  custodians  of  the  mental  organisation :  they  alone 
can  outride  the  tempests  of  life  ;  but,  on  the  other  hand,  they  may  be  drawn 
by  alluring,  deceptive  appearances  towards  the  mirage  of  rapid  ill-gotten 

1  Cathcart.  "  Psychic  Secretion  :  The  Influence  of  Environment."  Journ.  of 
Ment.  Science.  1919. 

2  Bohn.     La  no uvelle  psychologie  animale.     1911. 


CONSCIOUSNESS  329 

success,  or,  again,  they  may  be  disarmed  by  passionate  caresses.  In  the 
midst  of  this  contest  between  attractive  (sometimes  deceptive)  elements 
and  threatening  elements,  a  contest  that  is  ever  being  renewed  under  the 
most  diverse  circumstances,  the  well- organised  ego  proceeds  with  vigilant, 
selective  power,  in  constant  undisturbed  harmony  with  the  environment 
in  which  it  lives  (social  consciousness)  and  with  Nature,  from  which  it 
derives  its  primordial  elements.  Will,  after  all,  is  only  a  compromise  in  the 
individual  consciousness,  a  resultant  of  impulsions  and  inhibitions. 

How  many  desires  are  aroused  by  the  course  of  affairs  around  us,  desires 
whose  flame  is  extinguished  by  the  chilling  breath  of  education  and  upbringing, 
or  stifled  through  the  timely  perception  of  danger !  How  many  are  the 
tendencies,  how  many  the  aspirations  that  are  kept  in  check,  as  it  were,  by  a 
morning  mist  which  does  not  yet  permit  us  to  perceive  the  propriety,  the 
opportunity,  or  the  ways  and  means  of  realising  them !  How  many  timid  and 
cautious  explorations  do  we  make  before  we  turn  back  owing  to  insuperable 
difficulties,  or  to  the  veto  imposed  by  the  mere  possibility  of  compromising 
the  personal  ego !  Think  of  the  impulses  that  fade  away,  chased  com- 
pletely out  of  consciousness  by  the  strong  sentiment  of  duty !  And  the 
taunts  that  chafe  and  fret  the  innermost  soul,  stayed  by  that  inexorable 
power  which  governs  the  evolved  man,  mindful  of  his  social  obligations, 
holding  up  before  him  the  threat  to  the  integrity  of  the  ego  which  cannot 
withdraw  itself  from  the  biophylactic  law ! 

All  these  representations  derived  from  the  actual  experience  of  the 
moment  and  from  previous  individual,  family  and  environmental  experience, 
constitute  the  real  content  of  what  we  call  inhibition,  which  finds  its  founda- 
tion in  a  wider  association  of  ideas,  embracing  logic,  memory,  the  more 
evolved  sentiments  with  their  accompanying  notions,  and  all  the  complex 
structure  of  the  cerebral  mantle. 

We  will  leave  aside  the  inhibitions  that  concern  the  lower  centres,  to 
which  physiologists  have  particularly  devoted  their  attentions,  and  the 
reciprocal  inhibition  of  the  sensory  areas,  which  can  be  reduced  to  the  law 
of  displacement  of  potential,  and  give  our  attention  to  this  other  form  of 
conscious  inhibition  with  a  content  of  representations,  contrasts,  associations, 
memories,  and  logic.  It  is  an  integral  and  essential  factor  in  human  conduct. 

Both  impulsive  and  inhibitory  forces  are  directed  to  the  motor  field  of  the 
cerebral  mantle,  where  all  sensory  and  intellectual  representations  resolve 
themselves  into  motor  intuitions  and  subsequently  into  movements  and, 
as  a  whole,  into  conduct.  Motor  impulsions  are  intimately  bound  up  with 
the  sensory  functions  and  therefore  with  the  areas  which  fulfil  these  functions. 
Every  perception  contains  within  itself  the  rudiment  of  a  motor  intuition. 
The  motor  area,  in  which  all  sensations  and  their  intellectual  products  are 
translated  into  appropriate  movements  (according  to  the  fundamental 
psychological  law  of  attraction  to  that  which  is  beneficial  and  pleasant  and 
repulsion  from  that  which  is  harmful  or  painful  to  the  personality),  is  situated, 
as  already  shown,  if  not  quite  in  the  middle  of  the  brain,  at  least  on  a  line 
slightly  in  front  of  that  which  divides  each  hemisphere  into  two  equal  halves 


330  THE  MECHANISM  OF  THE  BRAIN 

(the  pre-Rolandic  convolution  and  the  intermediate  motor  area.  Vide 
Chapters  I.  and  III.). 

The  large  extent  of  mantle  lying  behind  the  pre-Rolandic  convolution 
constitutes  the  sensory  field  which  is  differentiated  into  as  many  areas  as 
there  are  senses,  these  being  veritable  workshops  dedicated  to  the  trans- 
formation of  the  cosmic  energies  emanating  from  the  world  which  surrounds 
us ;  it  is  at  the  same  time  the  field  of  the  emotions,  which  incessantly  build 
up  the  kinsesthesis,  the  fundamental  nucleus  of  the  consciousness. 

All  that  lies  in  front  of  the  motor  field,  with  the  exception  of  a  remnant 
of  the  old  central  organs  of  smell  (in  the  orbital  and  internal  portions  of  the 
hemisphere)  is,  as  the  writer  has  endeavoured  to  show  in  the  preceding 
chapters,  the  organ  where  new  and  powerful  conceptions  are  formed  with 
the  material  provided  by  the  sensory  organs  from  individual  and  collective 
experience  of  life  (interwoven  with  history,  tradition  and  culture).  It  is 
also  the  chamber  of  resonance  of  the  somatic  ego,  which  participates  in  all 
the  mental  processes,  and  it  consequently  serves  as  the  meeting-place  of  the 
products  of  work  of  the  sensory  areas,  variously  associated  and  co-ordinated ; 
it  is  the  throne-room  of  logic  which  draws  its  material  from  history,  utilising 
the  archives  of  the  cognitions,  sifting  the  emotions  and  impulses,  and  judging 
their  effects  in  the  light  of  individual  and  social  experience.  From  this 
cerebral  organ  emanate  the  vigour  and  the  dignity  of  the  ego,  which  sails 
along  more  or  less  smoothly  between  the  billows,  the  rocks  and  the  shoals  of 
life,  emerging  either  victorious  or  shipwrecked  ;  this  is  true  whether  we  speak 
of  the  ego  pervading  the  ranks  of  humble  workers  whose  combined  efforts 
give  the  measure  of  the  activity  of  a  country,  or  of  the  ego  that  raises 
humanity  into  a  new  and  higher  region  of  knowledge,  impressing  a  more 
rapid  movement  along  endless  paths  of  progress. 

With  this  anatomical  disposition  of  the  brain,  which  is  supported  by  the 
most  assured  and  controllable  facts  of  embryology,  comparative  anatomy, 
experimental  physiology  and  clinical  anatomy,  there  correspond  two  grades 
of  consciousness,  a  higher  and  a  lower.  The  lower  consciousness  moves  in 
the  shorter  circuits  of  the  sensory  fields  where  prevail  sensations,  images, 
relatively  simple  mental  constructions,  emotions,  desires,  acts  of  self- 
protection,  and  instincts,  which  sometimes  flame  into  passions.  The  higher 
consciousness  moves  in  wider  circuits,  forming  with  the  former  a  more  ex- 
tensive network  of  notions  and  experiences,  being  open  to  currents  which 
come  from  all  parts  of  the  cerebral  mantle.  The  pre-frontal  portion  of  the 
mantle  contributes  to  the  higher  consciousness  with  the  weighty  factors  of 
reason  and  the  more  lofty  and  evolved  sentiments,  as  summed  up  in  the 
sentiment  of  sociality.  The  sensory  consciousness  tends  preferably  to 
immediate  satisfaction  of  individual  needs ;  the  higher  consciousness  tends 
to  temper  the  impulses  of  the  other  with  social  tendencies  and  instincts. 
Excessive  predominance  of  the  lower  consciousness  confers  on  man  a  more 
brutally  egoistic  character,  which  sometimes  leads  to  criminality  in  the  most 
diverse  forms.  Prevalence  of  the  higher  consciousness  raises  egoism  to  the 
higher  sphere  of  human  solidarity,  leading  sometimes  to  genius,  which 


CONSCIOUSNESS 

synthetises  the  story  and  the  potentiality  of  the  race,  and  at  the  same  time 
opens  up  new  horizons  to  thought  and  new  fields  to  human  activity. 

This  twofold  form  of  consciousness  may  be  followed  step  by  step  in  the 
history  of  human  evolution  and  human  degeneration.  The  study  of  human 
disease  lends  confirmation  in  support  of  this  twofold  aspect  of  consciousness. 
If  we  trace  the  phylogenetic  history  of  both  modes  of  consciousness  in  relation 
to  the  two  cortical  fields,  we  arrive  at  conclusions  that  at  present  are  difficult 
to  combat.  The  sensory  field  is  first  to  be  developed :  with  it  we  have 
development  of  the  perceptive  capacity  and  the  motor  reactions,  and  whilst 
these  assume  in  the  main  the  character  of  fairly  simple  reactions,  yet  they 
show  a  progressive  development,  both  in  number  and  complexity,  that  keeps 
pace  with  the  growth  of  the  mass  of  the  cerebral  mantle.  Step  by  step,  from 
childhood  to  adolescence  and  maturity,  we  find  the  psychic  manifestations 
becoming  more  varied  and  better  co-ordinated,  and  reasoned  inhibition 
coming  into  play. 

These  inhibitions  coincide,  in  the  zoological  scale,  with  the  development 
of  the  frontal  lobe,  and,  in  ontogenetic  development,  with  the  mature  growth 
of  that  organ.  Thay  assume  the  reins  of  government  in  life  when  the  frontal 
lobes  reach  their  maximum  development  in  the  evolved  man  of  the  more 
advanced  races. 

Although  the  frontal  lobe  comprises  a  great  part  of  the  cerebral  hemisphere, 
it  has  no  direct  relation  with  the  peripheral  organs  of  sense,  and  for  that 
reason  cannot  discharge  sensory  functions.  That  does  not  mean  to  say, 
however,  that  as  this  new  part  of  the  neopallium  develops  the  sensory  field 
remains  stationary.  On  the  contrary,  a  marvellous  development  takes  place 
at  the  same  time  in  the  sensory  field.  We  have  already  given  examples  in 
proof  of  this  statement. 

From  the  functional  point  of  view,  all  the  senses  become  finer  and  more 
developed  with  the  progress  of  civilisation.  Tacitle  sensibility,  e.g.,  becomes 
more  delicate  and  highly  differentiated.  In  the  tactile  and  muscular  sensi- 
bility of  the  blind  we  have  an  example  of  the  development  of  which  this  sense 
is  capable.  The  case  is  reported  of  a  deformed  girl  whose  four  limbs  were 
represented  by  the  merest  stumps,  who  had  so  developed  the  tactile  sense 
in  the  tongue  and  mouth  that  she  was  able  with  her  tongue  and  lips  to  work 
a  thread  in  her  mouth  into  a  piece  of  lace.  So  far  as  the  sense  of  hearing  is 
concerned,  we  know  that  the  song  of  the  savage  is  monotonous  and  simple, 
consisting  essentially  of  a  few  notes  and  beats  in  a  deafening  combination 
of  stridulous  noises  in  which,  at  most,  some  little  respect  is  paid  to  rhythm. 
What  a  difference  from  the  melancholy  song  of  La  Traviata  or  the  voluptuous 
and  seductive  singing  of  Carmen,  or  the  desperate  and  vindictive  song  of 
Othello,  or  the  chattering  of  the  chorus  in  Falstaff\  What  a  variety  of 
accents,  what  an  inflexion  of  notes  and  motifs ! 

The  compositions  of  Rossini,  Verdi,  Wagner,  would  not  have  been 
possible  but  for  the  marvellous  development  of  the  sense  of  hearing  and  the 
sentiments  connected  therewith.  The  music  of  Pergolesi,  Rossini,  Verdi, 
Beethoven  and  Chopin,  reflecting,  as  it  does,  development  and  perfecting  of 


332  THE  MECHANISM  OF  THE  BRAIN 

the  auditory  field,  stands  in  the  same  relation  to  primitive  music  as  the 
capacity  of  civilised  races  and  people  who  have  been  trained  to  distinguish 
the  various  shades  and  blendings  of  colours  stands  in  relation  to  that  of 
primitive  peoples.  This  capacity  has  progressed  pan  passu  with  civilisa- 
tion. The  earliest  men  probably  distinguished  only  the  colours  of  wide 
vibrations  such  as  red  and  orange.  Other  colours  with  shorter  and  weaker 
vibrations  were  not  distinguished  till  a  later  period  (Geiger). 

There  is  thus  no  doubt  that  sensory  evolution,  with  its  anatomical 
substratum  in  the  posterior  regions  of  the  cerebral  hemispheres,  also  goes 
on  indefinitely ;  but  the  life  of  interhuman  relation,  the  tendency  towards 
reciprocal  understanding  of  minds,  the  great  intellectual  constructions,  the 
logical  pattern  of  thought  and  conduct  based  on  attention,  evocation, 
selection,  imagination,  co-ordination — in  other  words,  the  appraising  of  the 
marvellous  products  obtained  by  the  work  of  Nature  and  natural  forces  on 
the  sensory  brain — are  evidently  dependent  upon  the  frontal  lobes,  which 
evoke  and  utilise  all  these  products  in  the  construction  of  the  great  syntheses 
and  at  the  same  time  moderate  the  impulsive  or  reflex  activities  inherent  in 
each  individual.  In  this  way  man  proceeds,  on  the  one  hand,  to  perception 
of  Nature  and  the  infinite  voices  of  the  social  environment ;  on  the  other 
hand,  he  attains  to  the  most  complex  intellectual  syntheses,  and  to  an  ever- 
increasing  inventive  activity  which  is  directed  towards  the  overcoming  of 
difficulties  and  the  rendering  of  life  more  joyous  and  more  certain,  whilst  at 
the  same  time  he  becomes  more  capable  of  adapting  himself  to  the  environ- 
ment, tempering  individual  with  social  instincts.  Thus  it  comes  about  that 
the  primordial  impulse  of  each  man,  as  it  evolves  in  contrast  with  the  impulses 
of  other  men,  obeying  the  fundamental  biophylactic  law,  attains  by  degrees 
to  that  conduct  which  is  characteristic  of  the  truly  evolved  man,  conduct 
that  is  the  resultant  of  impulsions  and  inhibitions. 

One  may  represent  human  conduct  in  the  form  of  an  equation  into  which 
there  enter,  in  different  proportions,  the  two  forms  of  consciousness  already 
alluded  to.  If  we  suppose  conduct  to  be  represented  by  C,  the  sensory  and 
emotional  consciousness  by  S,  and  the  higher  (logical  and  sentimental)  con- 
sciousness by  I,  the  equation  will  be  C=S  :  I.  The  two  terms  S  and  I 
vary  very  much  in  different  individuals  and  in  different  ethnic  groups.  S 
may  be  excessively  developed  (strong  sensitivity  and  emotivity)  so  that 
this  term  will  be  represented  by  Sn,  whilst  at  the  same  time  I  will  be 
proportionately  less,  or  vice  versa. 

The  different  combinations  of  numerator  and  denominator  have  their 
counterpart  in  the  numerous  varieties  of,  and  outstanding  differences  in, 
individual  and  ethnic  characters.  Other  factors,  no  doubt,  enter  into  the 
structure  of  character,  but  all  may  be  brought  within  the  above  formula, 
which  comprises  perceptivity,  emotivity,  associative  capacity,  impulsivity, 
inhibition,  activity,  sociality.  The  value  of  life  is  in  proportion  to  the 
development  of  I  and  S,  between  which  there  should  be  a  perfect,  reciprocal 
understanding. 

We  still  know  but  little  of  the  obscure  work  of  milliards  of  cells  in  the 


CONSCIOUSNESS  333 

mantle  which  are  grouped  and  connected  with  one  another  in  a  wonderful 
manner.  Nevertheless  it  is  safe  to  say  that  all  the  work  of  the  human  brain 
is  the  resultant  of  these  two  energies — impulse  and  inhibition.  The  products 
of  this  contrasting  action  are  constantly  being  multiplied  and  renewed ; 
and  the  work  promoted  by  the  constant  renewal  of  the  physical  and  social 
environment  and  by  the  changing  circumstances  of  organic  life  always  entails 
new  co-ordinations  and  the  co-operation  of  additional  workers.* 

It  is  clearly  our  duty  to  promote  and  encourage  the  development  of  the 
brain.  The  evolutionary  progress  of  this  very  important  organ  coincides 
with  a  gradual  perfecting  of  the  sensory  powers,  which  enables  us  more  and 
better  every  day  to  grasp  and  appraise  the  world  in  which  we  live  ;  it  reveals 
itself  in  a  progressive  transformation  of  the  products  of  the  work  of  appre- 
hension (more  closely  connected  with  the  reflexes  and  instincts),  into  in- 
tellectual, sentimental  and  inhibitory  power,  which  is  based  essentially  upon 
more  extensive  association  and  co-operation. 

In  all  grades  of  scholastic  education  it  is  necessary  to  develop  the  per- 
ceptive and  retentive  capacities  on  the  one  hand,  and  the  associative,  attentive 
and  inhibitory  powers  on  the  other.  Modern  education  should  consist 
essentially  in  aiding  and  guiding  the  unceasing  development  of  the  general 
and  special  functions  of  the  brain  and  in  leading  the  individual  into  regions 
of  wider  and  more  effective  relations  with  the  physical,  social  and  ethnic 
environment.  Education  which  promotes  the  fullest  possible  development 
of  all  the  functional  capacities  will  lead  not  only  to  successful  acquisition  of 
knowledge  of  the  world  of  nature,  but  also  to  comprehension  of  the  responsi- 
bilities involved  in  discharging  the  duties  of  the  family,  social  and  national 
life,  i 

It  is  necessary,  in  other  words,  to  gradually  transform  the  primary  ego 
(Meynert),  which  is  prevailingly  instinctive  and  egoistic,  into  the  secondary 

*  This  formula  summarises  the  modern  conception  of  the  cerebral  localisations. 
In  the  writer's  opinion  it  is  not  made  any  clearer  by  the  introduction  of  the  term 
chronogenous,  which  expresses  a  very  obvious  fact,  although  it  is  insisted  upon  by 
Monakow  (Les  Localisations  cerebrales.  Wiesbaden,  1914).  Time  has  reference  to 
the  evolutionary  progress  of  the  brain,  and  has  little  to  do  with  the  actual  function 
of  the  evolved  brain.  In  order  to  understand  the  cerebral  function  we  must  take 
cognisance  of  the  spatial  factor  as  explained  in  Chaps.  I.  and  III.  The  chrono- 
genous  factor  has  reference  to  the  evolutionary  progress  of  the  nervous  system  and 
of  mind  in  the  historical  sense  ;  the  element  of  time  in  the  psychic  processes  should 
not  be  brought  into  the  question  of.  the  cerebral  localisations.  Physiologists, 
clinicians  and  histologists  have  long  taken  great  pains  and  carried  out  many 
researches  with  the  object  of  denning  the  various  localities  from  which  are  derived 
the  phenomena  of  the  life  of  the  nervous  system.  Apart  from  the  still  rather 
uncertain  and  contradictory  results  obtained  from  the  study  of  cytotecture,  every- 
thing goes  to  prove  that  the  appearance  of  any  new  organ  arising  in  the  course  of 
the  development  of  the  brain  is  counter-marked  by  the  utilisation,  on  the  part  of 
that  organ,  of  the  products  of  the  work  of  pre-existing  organs.  It  is  in  this  way 
that  we  get  an  extension  of  the  field  of  localisation  of  the  elementary  products  that 
go  to  make  up  the  more  complex  psychic  processes. 

1  L.  Aiidrizen.  "  On  the  Bases  and  Possibilities  of  a  Scientific  Psychology." 
Journ.  of  Ment.  Science.  1899. 


334  THE  MECHANISM  OF  THE  BRAIN 

ego  characterised  by  the  development  of  morality  and  of  higher  consciousness, 
which  assumes  the  government  of  life. 

The  fortune  of  an  individual  or  an  ethnic  group  is  greater  or  less,  according 
to  the  particular  capacity  to  penetrate  situations  (apperception) — in  other 
words,  it  depends  upon  the  extent  and  strength  of  the  associative  and  atten- 
tive faculties.  Ability  to  penetrate  the  innermost  sense  of  things  provides 
the  key  to  the  efficacy  of  a  single  action  or  of  the  whole  conduct,  either  of  an 
individual  or  of  an  ethnic  group. 

To  create  the  habit  of  superficiality  in  thinking  and  knowing,  as  happens 
in  many  of  our  schools,  is  but  to  prepare  the  way  for  conduct  that  is  liable 
to  be  swayed  by  overtures  and  advances,  because  superficial  knowledge  leads 
to  inconsistence  of  character,  and  to  hypo-morality,  and  is  linked  with 
emotivity  that  is  often  egoistic,  like  the  emotional  explosions  that  we  some- 
times witness  even  in  public  assemblies,  manifesting  itself  in  enthusiastic 
applause  to  the  more  or  less  affecting  speech  of  the  orator,  who,  by  oratorical 
artifice,  appeals  to  the  emotions,  although  the  speech  may  be  entirely  void 
of  any  content  of  practical  politics.  From  the  school  to  the  family,  to  the 
workshop,  to  public  offices,  and  to  the  higher  posts  in  the  state  and  in  the 
legislature,  the  character  of  the  nation  bears  everywhere  the  stamp  that  was 
impressed  upon  it  in  school. 

Consider  a  moment  the  attitude  of  Italy  in  the  earlier  stages  of  the  Great 
War.  The  ignorance  and  consequent  suggestibility  of  the  masses,  the  flabby 
consciences  of  certain  leaders,  the  lack  of  foresight  (inattention  and  super- 
ficiality of  judgment),  the  predominance  of  low  emotions  (vanity  and  pride 
in  some  cases,  and  fear,  indiflefen.ee  and  neglect  of  duty  in  others),  injustice 
(falsehood,  cruelty,  moral  weakness),  etc.,  were  able  for  the  moment  to  place 
a  veto  upon  the  great  and  genuine  virtues  of  the  stock,  subsequently  revealed 
in  the  heroism  of  her  soldiers,  who  smilingly  sacrificed  their  lives  for  their 
country,  and  in  the  noble,  dignified,  patient  resistance  of  a  people  enduring 
endless  suffering,  yet  throbbing  with  the  highest  and  purest  patriotic  senti- 
ment, virtues  which,  regaining  their  proper  dominion,  made  victory  assured. 

The  excessively  egoistic  conception  which  another  people  had  of  life,  the 
immeasurable,  overbearing  exclusiveness  of  the  race,  the  aggressive,  ferocious, 
insensible  haughtiness  in  the  exercise  of  the  right  of  force,  had  much  to  do 
with  the  ruination  of  that  people,  who  by  perseverance  and  labour  had 
succeeded  in  penetrating  every  region  of  the  world  with  the  products  of  its 
industry. 

To-day,  when  psychology  helps  us  to  explain  the  phenomena  of  history, 
it  is  our  duty  to  devote  careful  and  weighty  consideration  to  scholastic 
methods,  the  one  aim  and  object  of  which  should  be  to*  establish  in  each 
individual  the  sure  foundations  of  a  higher  consciousness,  embracing  the 
larger  conception  of  life,  which  is  an  aggregate  of  human  values,  associated, 
co-ordinated  and  acting  in  concert  with  one  another.  It  behoves  us  to  apply 
our  minds  assiduously  to  the  solution  of  this  problem  which  so  intimately 
affects  the  life  of  the  nation. 

We  must  change  our  ways.    Above  all  we  should  take  care,  in  every  grade 


CONSCIOUSNESS  335 

of  school,  to  get  rid  of  methods  and  systems  (perhaps  even  personnel)  that 
favour  slipshod  and  slovenly  learning,  that  are  concerned  solely  about  the 
quantum  necessary  for  the  examination,  drying  up  the  springs  of  noble 
sentiments,  and  paying  heed  only  to  the  expediencies  of  the  moment, 
methods  which  arrest  or  hinder  the  difficult  but  enthusiastic  work  of 
integration  and  development  of  the  higher  consciousness  and  the  powers 
of  attention,  which  on  the  contrary  should  be  developed,  encouraged  and 
brought  to  a  high  potential,  for  such  is  the  source  from  which  are  derived 
the  success  of  the  individual  and  the  fortune  of  the  race. 


INDEX  OF  SUBJECTS 


AFFECTIVITY    diminished     by    lesion    of 

frontal  lobes,  73 
Agnosia,  tactile,  46 
Agrypnia,  its  psychic  effects,  270 
Alexia  (word  blindness)  from  lesions  of 

parietal  zone,  36,  46 
Alogias   from   experimental   ablation   in 

monkeys,  259 
Amblyopia  in  monkeys   and  dogs  from 

mutilation  of  frontal  lobes,  195 
Amimia,  244 
Amnesia  (See  Aphasia),  asthenic,  237 

—  from  lesion   of   left  inferior  parietal 
lobe,  46 

Amphibians,      structure       of       nervous 

system  of,  95 
Angular  gyrus,  disturbances  from  lesions 

of,  34 
Anthropoids,  brain  (frontal  lobe)  of,  104, 

105,  107 
Aphasia,  amnesic,  51,  234,  237 

—  compensation  in,  126 

—  motor,  and  mental  integrity,  119,  241 

—  optic,  32 

—  sensory,  34,  36.     (See  Word -Deaf  ness) 
Apperception  (attentive  recognition),  and 

movements  associated  therewith,  193 

—  causes  of  failure  of,  259 

—  centre  of,  in  frontal  lobes,  80,  83,  334 
Apraxia,  from  lesion  of  inferior  parietal 

lobe,  36 

—  from  lesion  of  tactile  zone,  18 

—  in  aphasics,  244 
Archipallium,  11 

Area,     auditory     (acoustic-sensory     and 
acoustico-psychic),  18,  19 

—  for  images  of   objects   distinct  from 
those  for  images  of  words,  235 

—  intermediate,  precentral,  62 

—  motor,  16,  60 

comparative    limits    of,    in    man 

and  monkeys,  60,  71,  107,  110,  131 
intermediate,  25,   112,   116 

—  of    emotions    and    the    tactile    zone 
(Flechsig),  270 

—  of  frontal  evolution,  110 

—  of  reception  and  area  of  perception, 
30,  48 

—  olfactory,  19 

—  pre-f rental,  62,  112 

—  pre-Rolandic,   116 

—  projection  (Flechsig),  27 

—  somsesthetic  (of  Flechsig),  109,  270 

—  somatic  (of  Johnston),  11 

—  tactile,  16,  17 

— -  visual,  18,  22,  23 

Areas,  associative  (of  Flechsig),  25 

—  evolutionary  and  intellectual   evolu- 
tion, 23 


Areas,  myelogenetic,  26,  117 

—  posterior  cerebral,  importance  of,  in 
higher  mental  processes  (Flechsig),  82 

—  sensory,   in    cerebrum,   their   distinc- 
tion    into     sensory,    intermediate    or 
psycho-sensory,  19.     (See  Centre) 

Arrest,  centres  of,  78 

Assimilation,  mental,  255 

Association  centres  (Flechsig),  22,  25,  29 

—  paths,    between    frontal     lobes    and 
sensory  area  of  cortex,  198 

between  various  cells  of  cerebral 

cortex,  4 
Associations  and  frontal  lobes,  89 

—  between  cortical  centres  and   gusta- 
tory, acoustic,  visual,  etc.,  excitations, 
128 

—  capacity    for,    reduced    in    monkeys 
mutilated  in  frontal  lobes,  184,  251 

—  functional,  between  centres  of  move- 
ment of  head,  eyes,  and  ears,  133 

- —  classification  of,  219 

Astereognosis  from  lesion  of  tactile  zone, 

18 
Ataxia  from  lesion  of  frontal  lobes  (sig- 

moid  gyrus),  87 
Attention,  and  perceptive  process,  257 

—  diminution  of,  in  mutilated  monkeys 
and  in  idiots,  251,  256 

—  expectant,  133 

—  expectant  and  hallucination,  318 

—  frontal  lobes  organ  of,  70,  83 

—  in    relation    to    pleasure    and    pain, 
272 

—  motor  concomitants  of,  194 
Auditory    cortical    field,    differentiation 

of,  for  phonetic  images  of  things,  49 
Automatisms  and  reflexes,  10 
• —  and  the  unconscious,  319 

—  from  lesions  of  frontal  lobes,  73 

—  subcortical  and  cortical,  12,  13 


BABINSKI'S  sign,  absence  of,  in  hemi- 
paresis  from  lesion  of  inferior  frontal 
lobe,  36 

Biophylaxis,  256,  284 

Birds,  development  of  brain  (frontal 
lobes)  in,  95 

Blindness  from  cortical  lesion,  24 

—  psychic  (of  Munk),  24 

—  word  (Alexia),  36 
Brain.     (See  Cerebrum) 
Bridgemaiin,  Laura,  235 
Bulbs,  ocular.     (See  Eye) 
Bundle,  intellectual  or  psychic,  202 

-  fronto-occipital,  associative,  203 

—  superior   or  arcuate    longitudinal    or 
associative,  198 


337 


338 


INDEX  OF  SUBJECTS 


Bundle,  uncinate,  connecting  with  frontal 
lobe,  199.  (See  Fibres) 

Bundles,  associative  intraf  rental,  be- 
tween frontal  lobe  and  sensory  area  of 
cortex,  198 

—  projection,  effects  of  lesions  of,  49 


CAPSULE,  internal,  contains  projection 
fibres  of  frontal  lobe,  200.  (See  Mon- 
keys) 

Centre,  acoustic  or  phonetic,  of  articu- 
late sounds,  238 

—  auditory,  of  Wernicke,  34 

—  for  somatic  reflexes  of  the  emotions, 
270,  273 

—  frontal,     for    dilatation     of     pupils, 
194 

for  secondary  and  primary  sensi- 
bility (Flechsig),  25 

• •  for  secretions,  268 

of  sentiments  which  become  con- 
scious, 270 

—  —  for  respiration,  264 

-  for  viscera,  266,  267 

—  of  centres,  21,  79 

—  visual,  18 

—  visuo-psychic  and  visuo -sensory,  24. 
(See  Area) 

Centres,  auditory,  of  language,  32,  47 

—  cortical,  of  association  (Flechsig),  21, 
22,  25 

—  fictitious  inhibitory,  78 

—  inhibitory,  in  frontal  lobes,  85.     (See 
Inhibition) 

—  of  language,   disturbances    of,  affect 
entire  cerebral  functioning,  49 

—  subcortical,    their    function,    12,    13. 
(See  Areas) 

Cerebrum,  its  morphological  evolution 
and  weight,  8,  9 

—  intelligence   and   weight   of,   9.     (See 
Neopallium,  Grey  Substance,  Weight, 
Intelligence,     Hemispheres,     Haemorr- 
hages, Convolutions,  Cortex,  etc.) 

Character,  individual,  and  frontal  lobes, 
71 

—  nucleus  of,  314 

Children,  dreams  and  fibs  of,  223 

—  earliest    manifestations    of    language 
in,  230 

—  mechanism  of  reading  and  writing  in, 
239 

—  mental  evolution  in,  221 
Chimpanzee,  frontal  lobe    (third   frontal 

convolution)  of,  105 
Chorea,      Sydenham's,      and     emotional 

attitudes,  278 
Chronogenous     and    spatial    element    in 

cerebral  localisations,  333 
Cibus,  lower,  brain  and  frontal  lobe  of, 

106 
Cingulum,    association-bundle     of     rhin- 

encephalon,  198 
Cinocephalus,      development      of      brain 

(frontal  lobe)  of,  106 
Circulation,  effect  of    cortical  excitation 

upon,  266 


Circus  movements,  from  lesions   of   sig- 

moid  gyrus,  87 
not    dependent    upon    inhibition, 

78,  87,  191 
Claustrum,  bundle  of  fibres  in  connection 

with  frontal  lobe,  206 
Climate  and  the  elements  from  which  it 

results    (light,  temperature,  electricity, 

winds,    etc.).     Its    influence    on     the 

psychic  function,   on  insanity,  crimes, 

suicide,  etc.,  261 
— •  influence  of  great  heat  and  great  cold, 

269 
Clinical    histories    of     dogs,    foxes    and 

monkeys,    deprived   of    frontal   lobes, 

169 

Cold,  disintegrating  action  of,  269 
Colloids,    importance    of,    in    the     vital 

phenomena,  3 
Colours  and  evolution  of  vision,  332 

—  distinguished  by  monkeys,  130 
Compensations,    functional,    in     cerebral 

cortex,  22,  126,  142 
Complexes,  sensory  and  motor,  13 

—  psychic,  216,  318 

Conceptions,  abstract,  formation  of,  247 
Concomitants,  somatic,  of  pleasure  and 

of  pain,  273 

Conconscious,  conception  of,  317 
Conduct,  logical  character  of,  303 

—  individual,  and  frontal  lobes,  71 
Consciousness,  and  images,  12 

—  and    propagation    of    stimulus    to    a 
large  number  of  nerve-cells,  326 

—  genesis  and  localisation  of,  10,  15,  16, 
82,  302,  311,  312 

—  higher  and  lower,  evolution  of,  330, 
331 

—  successive    mutations    of,    analogous 
with  physical  and  physiological  facts,  2 

—  the     unconscious      or      subconscious, 
224,  317 

Contrast,  psychic,  in  mental  associations 
and  in  delusions  and  obsessions,  222, 
256,  311,  329 

Convolution,  ascending  parietal,  disturb- 
ances from  lesions  of,  46 

—  supra-marginal,      disturbances      from 
lesions  of,  34 

Convolutions,  and  functions  do  not  coin- 
cide, 108 

—  and  sulci,  frontal,  115 

—  temporal,  physio-pathology  of,  51 

—  temporal,    disturbances    from    lesions 
of,  34 

Corpus  striatum,  in  fishes,  94 

Cortex,     cerebral,     development     of,     in 

batrachians,  14 

in  vertebrates,  9,  11 

in  the  various  zones  and  its 

histological    structure    in    relation    to 

function,  116 

—  degenerative  dissolution  of,  in  inverse 
order  from  evolution,  117 

—  differentiation    and    functional    local- 
isation in,  14 

—  sensory,   and   psychic   content    of  the 
emotions,  271 

—  association-paths    between    frontal 
lobe  and,  198 


INDEX  OF  SUBJECTS 


339 


Crime,  influence  of  climate  upon,  261 

Currents,  electric,  excessive  strength  of, 
a  source  of  error  in  experimental  in- 
vestigations, 132 

Cytotecture  of  cortex,  17,  20,  23,  30,  61, 
89,  90 

—  of  frontal  lobe,  117.     (See  Histotecture) 


DEAFNESS,   word.     (See  Word-Deafness) 
Decortication  of  frontal  lobes  left  in  situ, 

135 

Defsecation,  cortical  centre  of,  267 
Degeneration,  anthropological,   113,  114, 

127 

• —  descending,  in  study  of  cerebral  local- 
isations, 29 

Degenerative  processes  in  cerebrum    after 
destructive      foci      and      experimental 
lesions,  127 
Deglutition,  cortical  centre  of,  in  relation 

with  respiratory  centre,  267 
Deliberation,  action  and  conduct,  248,  309 
Delusions,  extraneous  elements  in  reason- 
ing process,  258 

—  from  associations  by  contrast,  223 
Dementia  and  law  of  dissolution,  114 

—  associated  with  psychic  blindness  and 
word-deafness    (auditory   aphasia),    31, 
44 

—  accompanied    by    degenerative    histo- 
logical  changes  in  pyramidal  cells,  113 

—  post-epileptic  :    clinical  case,  57 
Destructions,  experimental,  in  cerebrum, 

proximate  and  remote  effects  of,  125 
Diaschisis,  35,  87,  90,  122,  142 

—  and  bilateral  homonymous  hemianop- 
sia,  196 

Differentiation,  and  co-operative  associa- 
tion, law  of,  15 

—  functional,  in  cerebral  cortex,  15 
Discipline,  normative,  of  Wundt,  254 
Disintegration  and  pain,  271 
Dislogias,  256 

Distance,  perception  of,  in  infants,  25 
Dogs,    clinical    histories    of    experiments 
upon,  137 

—  development  of  brain   (frontal  lobes) 
of,  97 

Dolphin,   development  of   brain   (frontal 

lobe)  of,  96,  107 
Double  personality,  322 
Dreams,  and  "  Repressed  Wish,"  320 

—  of  infants,  223 


E 


EARS,  movements  of,  provoked  by  stimu- 
lation of  certain  excitable  areas  of 
frontal  lobe,  191 

Education,  human,  essence  of,  333 
—  of    animals   in    new    associations    for 
purpose    of    re-examination    after    ex- 
cision of  frontal  lobes,  88 
Ego,  primary,  secondary,  Meynert,  333 
Electrons,  theory  of,  in  relation  to  psych- 
ology, 1,  2,  3,  4,  5 


Emotions,  and  kinsesthesis,  273 

—  and  sentiments,  260,  280,  289 

—  and  the  sensory  cortex,  their  psychic 
content,  271 

—  and  the  various  "  grades  "  of  feeling,  213 

—  and  touch,  area  of  (Flechsig),  270 

—  as  extraneous  elements  in   reasoning, 
258 

—  evolved,  270 

—  in  monkeys  deprived  of  frontal  lobes, 
185 

—  in  relation  to  associative  powers,  84 

—  organic  basis  of,  not  in  frontal  lobe, 
65,  83,  84,  89 

— *-  the  two  theories  of,  as  regards  nature 

and  seat,  the  somatic  theory  and   the 

psychic  factor,  274 
Emotivity,  after  lesions  of  frontal  lobes, 

73,  89 

Energetics,  263 
Energy,  psychic,  in  relation  to  laws  of 

natural  energy,  213 
Epileptic  attack,  dilatation  of  pupil  in, 

192 
from  electric  stimulation  of  frontal 

lobes,  75,  76 
Equivalents,     biological,     nervous     and 

psychic,  8,  9 
Ether,    and    electro-magnetic,    luminous 

and  nervous  waves,  1,  3,  10 
Evolution,  mental,  in  infants,  212,  221 

—  of   neuro -muscular    system,    6.       (See 
Various  Sensory  Organs) 

Excitable   area    of  frontal   lobe    and   its 

significance,  187,  191 
Experience,  individual    (ontogenetic)  and 

inherited  (phylogenetic),  215 

—  not  made  use  of  in  mutilated  monkeys, 
251 

—  result    of    relations    in    simultaneity, 
resemblance,  etc.,  252 

—  utilisation  of,  306 

Extension,  movements  of,  from  pleasur- 
able excitations,  279 
Extra-logical  (or  moral)  objects,  253 
Eye,  morphological  evolution  of,  in  rela- 
tion to  psychic  development,  6,  7 

—  movements  of,  provoked  by  stimula- 
tion of  certain  excitable  areas  of  frontal 
lobe,  190,  191 

—  visual  disturbances  in  dogs  and  mon- 
keys after  frontal  mutilations,  195 


FEAR,  genetic  conditions  of,  277 

—  in  monkeys  mutilated  in  frontal  lobes, 
185 

Fibres,  associative,  30 

—  associative,    deficient    in     pre -frontal 
area,  112 

—  projection,  of  frontal  lobe,  200.     (See 
Bundles.) 

Fibs  of  young  children,  223 

Fields.     (See  Area  and  Centres) 

Flexion,  movements  of,  from  unpleasant 

excitations,  279 
Fishes,   structure   of  encephalic    nervous 

system  in,  94 


340 


INDEX  OF  SUBJECTS 


Fissure  of  Rolando,  correspondence  be- 
tween crucial  sulcus  and  presylvian 
sulcus'of  animals  and,  97 

— position  of,  in  monkeys,  107 

(See  Sulci  and  Convolutions) 

Form,  perception  of,  in  infants,  25 
Frontal  lobe,  a  centre  of  association  and 

co-ordination,  22 
— •  —  associative    paths    between,     and 

sensory  field  of  cortex,  1 98 
evolution,  morphology,  and  struc- 
ture of,  94,  118 

functional  value  of  left  and   right 

(language,  intelligence,  etc.),  118,  119 


GAIT,  influence  of  inhibition  on,  325 
Ganglia,  evolutionary  story  of,  5,  8 
Glands,  influence  of  cortex    (tactile  zone) 
on  secretion  of,  268 

—  lachrymal.     (See   Tears) 

—  mammary.     (See  Milk) 

—  salivary.     (See  Saliva) 

Gorilla,  frontal  lobe  and  third  frontal  con- 
volution in,  105.  (See  Monkeys) 

Grey  substance,  relative  development  of, 
in  man  and  animals,  10 

Grief  and  joy,  273,  275,  279 

Gustatory  area,  19 

Gyrus,  angular,  disturbances  from  lesions 
of,  34 


H 


HAEMORRHAGE,     cerebral     symptoms      of 

transitory  shock  from,  125 
Hallucinations,  alogia  resulting  from,  256, 

257,  258 
—  and  personality,  322 

—  visual,  unilateral,  141 

Hearing,  cerebral  localisation  of  auditory 
sensibility,  18 

—  disturbances  of,  from  lesions  of  parietal 
lobe,  34 

temporal  lobe,  51 

—  evolution  of,  331 

Heart,  influence  of  cortex  upon,  266 
Heat,  disintegrating  action  of,  269 
Hedonism,  296 
Hedonistic  sensations,  290 
Hemiagnosis,  tactile,   in  parietal  lesions, 

46 
Hem i anaesthesia   from   lesion    of   inferior 

parietal  lobe,  36 
Hemianopsia,       bilateral       homonymous, 

from  lesion  of  inferior  parietal  lobe,  36 
—  in  dogs  and  monkeys  mutilated 

in  frontal  lobes,  195 
Hemiparesis.     (See   Paresis) 
Hemiplegics,  apparent  emotivity  of,  277, 

278 
Hemispheres,    cerebral,   differentiation   of 

right  and  left,  119,  120 
Hieroglyphics  in  evolution  of  writing,  233 
Histotecture,  according  to  Brodmann,  111 

—  geographic,    of    cerebral   cortex,    111. 
(See  Cytotecture) 


Horse,  development  of  brain  (frontal  lobe) 
of,  100 

Humanity,  sentiment  of,  296 

Hunger  and  thirst,  and  pleasure  and  pain, 
269,  271 

-  —  fundamental  emotions  con- 
nected with  material  exchange  and 
chemical  conditions,  269 

Hyperlogical,  or  aesthetic,  objects,  253 

Hypnotism  and  the  unconscious,  317,  318 

Hypologia,  257 

Hysteresis,  associative,  3 

Hysteria  and  the  subconscious,  317 

Hystological  structure  and  psychological 
facts,  30 

Hystotectural      geography     of      cerebral 
cortex,  110 

—  type  of  Brodmann.     (See  Cytotecture) 


IDEAS,  general,  and  concrete  images,  217 
Idiots,     behaviour     of,     compared     with 

mutilated  monkeys,  250 
Illiterate,    effects    of   lesions    of    parietal 

lobe  in  the,  48,  50 
Images,  and  consciousness,  12 

—  concrete,  words,  and  general  ideas,  217 

—  elaboration     of,    in    sensory    cerebral 
areas,  19,  20 

—  elementary  constitution  of,  4 

—  memory,  237 

—  mnemonic,    produced    by    perception 
and  associated  in  the  cerebral  centres, 
21 

—  visual,  formation  of,  24 

—  word   (auditory,   visual,    kinsesthetic), 
237 

—  word,  Marie's  views  against,  244 
Imagination,  creative,  223 
Imbeciles,  lack  of  sociality  in,  288 

—  natural   history    of   human    evolution 
reproduced  in,  313 

Imitation  as  a  social  law,  294 
Impressions,  varying  effect  of,  in  different 

individuals,  2 

Impulses  and  contrast,  327,  332,  333 
Impulsions  and  inhibitions  in  human  con- 
duct, 309,  327 

Index  of  variability  in  frontal  lobe,  119 
Indifference,  from  tiredness,  271 

-  psychic,  in  monkeys  from   lesions  of 
frontal  lobes,  73 

Indifferent  sensations,  272 

Inhibition,  cerebral,  absence  of,  in  mon- 
keys mutilated  in  frontal  lobes,  185 

and  impulses  in  human  conduct, 

333 

—  —  foundation  of,  329,  331 

in  the  various  cerebral  regions,  324 

—  conscious,  329 

-  frontal  lobes  and,  318,  331 

-  reciprocal,     of     sensory    areas,      329. 
(See  Centres) 

—  centres  of,  78 

—  cerebral,  309,  310 
Insomnia,  psychic  effects  of,  270 
Instinct  of  self-preservation,  269,  290 
Instincts  and  sociality,  289 


INDEX  OF  SUBJECTS 


341 


Intelligence,  and  emotions,  283,  284 

—  and  language,  209 

—  and  weight  of  brain,  9 

—  disturbances   of,   from    lesions    of    left 
inferior  parietal  lobe,  46 

—  evolutionary  phases  of,  10 

—  in  lower  creatures,  307 

—  in  man  and   animals,  applicability  of 
experiments  relating  to,  127 

-  localisation  of,  15,  16,  19,  20 
Interference  in  mental  associations,  223 
Internationalism  and  sociality,  287 
Interrupter,   hand,  in   electrodes    used  in 

experiments,  136 
Intestine,   movements    of,  in    relation  to 

cortical  stimulations,  267 
Invariability  and  variability  of   reactions 

in  progressive  evolutions,   12 
Irresistibility  of   movements  from  lesions 

of  frontal  lobes,  72,  73 


JOY  and  grief,  genetic  conditions  of,  262, 

275,  276,  278 

Judgment,  and  deliberation,  224,  248,  309 
—  defects    of,    from    lesions    of    frontal 

lobes,  73 


K 


KELLER,  HELEN,  235 

Kinaesthesia,    and    emotions,    sentiments 

and  images,  262,  273 
—  and  tactile  sphere,  65 
-  centre    of,   according   to   Flechsig,   in 

frontal  lobes,  82 
Kinaesthetic  sense,  263 


LAMB,  development  of  the  brain  (frontal 

lobes)  and  motor  zone  in,  103 
Language,  and  intelligence,  209 
—  and  left  cerebral  hemisphere,  119,  120 

—  and  phenomena  of  compensation  after 
cerebral  lesions,  126 

—  and  sociality,  291 

—  cerebral  localisation  of,  19,  32 

—  internal,  242 

—  lesions  in  areas  of,  affect  entire  cerebral 
functioning,  49 

—  motor  zone  for,  63 

—  reconstruction  of   cerebral  mechanism 
of,  19,  28,  29 

—  visual  and  auditory  cortical  areas    of, 
47,  48 

-  See    Aphasia,    Paraphasia,    Paralogia, 

etc. 

League  of  Nations  and  sociality,  287 
Liberty,  sentiment  of,  291,  296 
Light,   formation   of    visual    images,    24. 

(See  Climate) 
Lobe,  frontal,  a  centre  of  association  and 

co-ordination,  22 
associative     paths     between,     and 

sensory  field  of  cortex,  198 


Lobe,  frontal,  evolution,  morphology,  and 
structure  of,  94 

-  functional  value  of  left  and  right 
(language,  intelligence,  etc.),  118,  119 
—  inferior    parietal,    symptomatology    of 
lesions  of,  32 

—  left     temporo-sphenoidal,    destructive 
lesions  and  clinical  cases,  51 

—  influence     of,     on     thought 
(language),  59 

-  temporal,  psycho -pathology  of,  50 
Localisation  of  intelligence  and  conscious- 
ness, 15,  16,  19,  20 

Localisations,  cortical,  and  post-operative 
phenomena,  154 

—  linguistic,  chronogenous  and  spatial 
elements  in,  333 

—  in  relation  to  diaschisis,  122 

• sensory,  15,  16,  18,  19 

Logic,    disturbances    of,    in    pathological 
processes,  255 

—  extralogical    (moral)    and  hyperlogical 
(aesthetic)  objects,  253 

—  nature,  function,  and  development  of, 
252 

-  obsessions,  a  disturbance  of,  255 
Lying,  a  phenomenon  of    creative   imag- 
ination in  children,  223 


M 


MEMORY,  and  perception,  30 

—  associative,  a  factor  in  variability  of 
reactions,  8 

—  defects    of,    from    lesions    of    frontal 
lobes,  73,  88,  251 

-  in  monkeys  after  mutilation  of 
frontal  lobes,  184 

—  motor,  visual,  etc.,  219 

—  undisturbed  after  slight  frontal  lesions, 

Mesencephalon,   volumetric   relations   be- 
tween neencephalon  and,  10 
Methods  of  investigation  of  frontal  lobes 

121 
Milk,  psychic  influences  and  secretion  of, 

268 
Mnemonic    residua,   emotional,    in   ideas 

84 

—  or  traces  of  previous  sensations   8 

16 
Monkeys,  development  of   brain  (frontal 

lobe)  and  the  question  of  a  third  frontal 

convolution  in,  105 
—  effects     of     experimental     lesions    in 

trained    as   compared   with   untrained 

130,  131 

-  experimental    and  clinical  histories  of, 
after  mutilation  of  frontal  lobes,  137 

-  extent  of   cerebral  cortex  in,  as  com- 
pared with  man,  107 

-  psychology  of,  183,  250 
Morals  and  politics,  313 

Motor  function,  restricted  compensation 
of,  after  cerebral  lesions,  126 

Mutilation  of  cerebrum,  proximate  and 
remote  effects  of,  121,  123 

frontal  cortex,  effects  vary  accord- 
ing to  extent  of,  135 


342 


INDEX  OF  SUBJECTS 


Myelinisation  and  evolution  of  intelligence, 
29 

—  of  cerebral  fibres,  25 

—  of  spinal  bundles,  15 
Myelotecture,  cerebral,  117 
Myxine,  structure  of  pallium  in,  95 

N 

NEENCEPHALON,  volumetric  relations  be- 
tween mesencephalon  and,  10 

Neothalamus,  12 

Nervous  system,  evolution  of,  1,  6 

New  nervous  organs  utilise  functional 
products  of  pre-existing  nervous  organs, 

Nucleus     caudatus,     relations      of,     with 

frontal  lobe,  203 

-  lenticular,    relations    of,   with    frontal 
lobe,  204 


0 


OBSESSIONS,  illogical  nature  of,  255 

Olfactory  area,  evolution  and  localisation 
of,  11,  19 

Ontogenesis  and  phylogenesis  of  nervous 
system,  9 

—  perceptive,  215 

Operation,  extent  of   cerebral  mutilation 
in  relation  to  effects  of,  135 

Operculum,    Rolandic,    projection    fibres 
in,  201 

Optic  lobes  in  frogs,  14 

Orang-utang,  extent  of  cortex  in,  as  com- 
pared with  human  cortex,  107 

Organisation,  economic,  and    society,  294 

Organs  of  the  senses,  evolution  of,  6 

• —  of  recent  development  utilise  products 

of  pre-existing  nervous  organs,  14 
—  sexual,  cortical   representation  of,  267 

Ox.     (See  Ruminants) 


PAIN,  aversion  to,  271 

—  and    pleasure,    elements    from    which 
they  result,  271 

Pallium  membranosum  in  lower  fishes,  94 
Paralogia  and  lesions  of  temporal  lobe,  58 
Paraphasia  and  lesions  of  left  inferior 

parietal  and  temporal  lobes,  35,  37,  58 
Paresis  (hemi-)  from  lesion  of  left  inferior 

parietal  lobe,  35 
Parietal  syndrome,  32 
Passion,  emotions  and,  284 
Pathology,  mental,  and  the  subconscious, 

318 
Perception,   a    process   of    association   of 

various  components,  30 

—  defects  of,  in  monkeys   mutilated    in 
frontal  lobes,  183 

—  sensory,  and  apperception,  80 
involuntary        (immediate),        and 

voluntary  perception  with  attention 
(apperception),  movements  associated 
with,  193 

Perception    and     reception,    relation    be- 
tween, 30,  48 


Personality,  duplication  of,  322 
• —  organic,  263 

—  psychic,  alterations  of,  through  para- 
lysis of  cortical  field  of  kinsesthesis,  66 

growth  of,  216 

Petromyzon,  cerebral  structure  of,  95 
Phantasy,  psychic  elements  of,  19,  218 
Phrenasthenics,  mode  of  language  of,  231, 
232 

—  structural   and    histological   details  in 
brains  of,  113,  117 

Phylogenesis  and  ontogenesis  of  nervous 
system,  9 

—  social,  215 

Pleasure   and   pain,   integrative   and  dis- 

integrative  factors,  as  primordial  forms 

of  emotion,  262,  270,  271 
Pleiads,  isodynamic,  of  Cajal,  327 
Plethysmograph,  emotions  and  the,  262 
Polarisation,     psychic,     and     association 

through  contrast,  222 
Pole,  frontal,  a  small  part  of  pre -frontal 

lobe,  79 

Politics  and  morals,  313 
Precentral  area,  intermediate,  62 
Pre -frontal  area,  62 
Pre-Rolandic  area,  116 
Processes,     degenerative,    cerebral,    after 

destructive      foci      and      experimental 

lesions,  127 

—  logical,  in  monkeys,  185 
Projection  fibres  of  frontal  lobe,  200 
Protoplasm,  constitution  and  differentia- 
tion of,  5,  8 

Psychic  function  in  man  and  animals, 
applicability  of  experimental  findings 
to,  127 

Psychism  and  tropism,  3,  7 

—  in  lower  creatures,  305 
Psycho-analysis  and  the  unconscious,  317 
Psychology,  comparative,  and  the  appli- 
cation of  experimental  findings  t-c  the 
human  subject,  129,  209 

Psycho-reactive  function.  (See  Associa- 
tion) 

Pupils,  dilatation  of,  in  epileptic  attack, 
192 

frontal  centre  for,  194 

—  mechanism  of,  192 

—  movements  of,  provoked  by  stimula- 
tion of  certain  excitable  areas  of  frontal 
lobe,  190,  191 

—  relations  of,  with  facial  nerve,  194 

—  state  of,  in  relation  with  mental  pro- 
cesses (attention,  evocation,  etc.),  195 

Putamen,  relations  of.  with  frontal  lobe, 
204,  207 


Q 


QUANTITY,  in  psychic  phenomena,  212 


R 


RABBIT,    development    of    brain    (frontal 

lobes)  of,  96 
Races,  human,  variation  of  frontal  lobe 

in,  118,  119 


INDEX  OF  SUBJECTS 


343 


Rat,  development  of  brain  (frontal  lobes) 
of,  96 

Reactions,  chemical,  physical,  or  me- 
chanical nature  of,  in  living  creatures,  7 

Reading,  cortical  area  of  visual  images 
and  graphic  signs  of  words,  31 

—  mechanism   of,  in   infants,   239.     (See 
Alexia. 

Reason,  variability  and  invariability  of, 
in  various  creatures,  12 

—  genesis  of,  386 
Reasoning,  224 

Re-education,  after  cerebral   mutilations, 

124 

Reflexes,  automatism  and,  10 
— •  rapidity    of,    in    relation    to    cerebral 

inhibitory  action,  85,  86,  88 
Region.     (See  Area,  Centre,  Field,  etc.) 
Relation,  life  of,  in  lower  creatures,  303 
Religion,  passion  in,  284 
Reptiles,    structure    of     central    nervous 

system  of,  95 
Respiration,  cortical  area  associated  with, 

264 

Restraints.     (See  Inhibition) 
Retina,  area  of  cortical  projection  of,  24 
Ruminants,  frontal  lobes  poorly  developed 

in,  98 


SALIVA,  secretion  of,  arising  from  cortical 

and  psychic  excitation,  268 
Seasons,  influence  of,  on  psychic  functions, 

261 
Secretions,    influence    of    cerebral    cortex 

upon,  268 

Self,  primary  and  secondary  (Meynert),  333 
Sensations,  and  cerebration,  224 
• —  hedonistic,  in  education,  290 

—  indifferent,  272 

Sense,  kinaesthetic,  263.     (See  Kinsesthesis) 
Senses,   special,  cerebral  localisations  of, 

16,  18,  19 
Sensibility,  auditory.     (See  Hearing) 

—  differential,  a  new  factor  of  variability 
of  reactions,  8 

—  tactile.     (See  Touch) 

—  visual.     (See  Vision) 

Sensory  field  of  cortex,  associative  paths 

between  frontal  lobe  and,  198 
Sentimentality,  frontal  lobes  and,  285 
Sentiments,    emotional    and     intellectual 
components  of,  281,  282 

—  in  monkeys  deprived  of  frontal  lobes, 
186 

Sex,  variations  in  frontal  lobe  according 

to,  118,  119 
Sexual  functions,  their  <c  representation  " 

in  cortex,  267 
Sheep,    development     of     brain    (frontal 

lobes)  in,  102,  104 
Shock,    in    experimental     investigations, 

125 
Sight,  power  of,  in  various  animals,  6,  7 

—  cerebral  localisation  of,  18 

—  development  of,  in  infants,  25 
Sledge,    Du     Bois-Reymond,    in    experi- 
mental investigations,  136 


Sleep,     chemical     nature     of     conditions 

which  induce,  269 
Smell,  cerebral  localisation  and  evolution 

of,  11,  19 

Social  sentiment,  286,  295 
Sociality  and  instincts,  289 

—  and  League  of  Nations,  287 

—  disappearance    of,    in     imbeciles    and 
mutilated  monkeys,  288 

Somatic  area  of  Johnston,  11 

—  concomitants  of  pleasure  and  of  pain, 
273 

—  phenomena,  the   physical  components 
of  emotion,  279 

Sorrow  and  gladness,  275 
Space  and  time  in  cerebral   localisation, 
333 

—  and  spatial  relations,  perception  of  in 
infants,  25 

Speech,  central  organ  of,  on  foot  of  third 
frontal,  109 

—  internal,  242 

—  its     intrinsic      constituent      elements 
(auditory,  visual  and  kin  aesthetic)  and 
their    associative    inter-relations,     238. 
(See  Language) 

Sphincter,  anal,  cortical  centre  of,  267 
Spleen,    contractions    of,    in    relation     to 

cortical  excitation,  267 
Stereo tropism ,  7 
Stereotypisms,    from    lesions    of    frontal 

lobes,  73 

—  in  monkeys  mutilated  in  frontal  lobes, 
186 

Stimuli  and  functional  differentiation,  9 

Stomach,  movements  of,  from  cortical 
excitations,  267 

Subconscious,  the,  and  subcortical  auto- 
matisms, 13 

products  of,  317 

Succession  of  ideas  in  content  of  con- 
sciousness, law  of,  225 

Suicide,  influence  of  climate  upon,  261 

Sulcus,  crucial,  the  analogue  of  fissure  of 
Rolando,  97 

—  frontal  and  pre -frontal,  116 

—  presylvian,  the  analogue  of  fissure  of 
Rolando,  97.      (See  Fissure    and    Con- 
volutions) 

Surprise,  part  played  by,  in  emotion,  276 

Sygmoid  gyrus,  and  organic  phenomena 
of  emotion  84 

circus  movements  from  lesions  of, 

87 

proximity  of,  to  frontal  lobe,  129 

Symbolic  writing  (pictography),  233 

Symbols,  word,  of  objects  and  of  relations 
between  objects  and  images,  241,  248 

Sympathetic  system  and  emotional  re- 
action, 279 

Syndrome,  parietal,  32 

Syntheses,  psychic,  and  cerebral  localisa- 
tions, 21,  22 

Synthesis  of  syntheses,  248 


TACTILE  agnosis,  46 
—  area,  16,  17 


344 


INDEX  OF  SUBJECTS 


Tapetum,  symptomatology  of  lesions  of, 

42 

Taste,  cerebral  area  of,  19 
Tears,  secretion  of,  in  relation  to  cortical 

stimulation,  268 
Temperature.     (See  Climate) 
Territories,  cortical,  embryological,  26 

intermediate  and  terminal,  27 

Thalamus  opticus,  development  of,  15 

•  —  psychic  facts  and,  12 

—  —  relations  of,  with  frontal  lobe,  201, 
202 

Third  frontal  convolution,  question  of,  in 

monkeys,  105 
Thirst  and  hunger,  fundamental  emotions 

connected  with  material  exchange  and 

chemical  conditions,  269 
Thought,    association-centres   the    organs 

of,  according  to  Flechsig,  81 
-  influence  of  temporal  lobe  upon,  59 

—  in  mutilated  monkeys   and  in   idiots, 
315 

—  laws  and  elements  of,  and  their  origin, 
215,  216,  253 

—  origin  of,  10 

—  unconscious,  302 

Thrombosis,      cerebral,      and     transitory 

symptoms  of  shock,  125 
Tics  in  monkeys  mutilated  in  frontal  lobes, 

186 
Time  and  space  in  cerebral  localisations, 

333 

—  of  reaction,  after  removal  of  frontal 
lobe,  324 

Tiredness,  physical,  and  psychic  indiffer- 
ence, 272 

Tone,  emotional,  pleasant  or  unpleasant, 
in  all  psychic  facts,  272 

—  vital,  of  individual,  275 

Touch,  cerebral  localisation  of  sense  of,  16 

—  disturbances  of,  from  lesion  of  post- 
central  convolution,  34 

—  refinement  and  development  of,  331 
Trance  and  the  subconscious,  319,  322 
Tropism,    relation    of,    to    colloidal    sub- 
stances, 3 

—  to  emotion,  260 

—  reflexes,  automatism,  and,  13,  14 


Unconscious,  the  constitution  of,  284,  316 
Uniformity,   perceptive,   and   the   law    of 

variation,  4 
Uterus,    movements    of,    and    points     of 

cortical  excitation,  267 


VAGINA,    movements    of,    and    points    of 

cortical  excitation,  267 
Variability  and  invariability  of   reactions 

in  progressive  evolution,  12 
-  in  frontal  development,  118 
Variations,  law  of,  in  relation  to  perceptive 

uniformity,  4 

-  kinetogenetic,  in  evolution,   7 

-  physiogenetic      (chemical),      in 
evolution,  7 

Vascular  alterations  in  emotion,  266 

Vasomotor  phenomena  and  emotions  277 
278 

Vesical  movements  represented  in  cor- 
tex, 267 

Viscera,  representation  of,  in  cerebral 
cortex,  267 

Vision,  acuteness  of,  in  various  animals,  7 

—  cerebral  localisation  of,  18,  23 

—  development  of,  in  infants,  25 

—  disturbance  of,  in  dogs  and  monkeys 
after  mutilation  of  frontal  lobes,  195 


W 

WEIGHT  of  brain,  intelligence  and,  9 
Will,  and  frontal  associative  centres,  83, 
329 

-  attentive,  247 
Word-deafness  from  temporal  lesions,  51 

reciprocal   relations   between,   and 

dementia,  50 

(sensory  aphasia),  32,  35,  242 

Word-images.     (See   Images) 
Writing,  centre  for,  61,  62,  109 

—  mechanism  of,  in  children,  239 

—  relations  between,  and  centre  for  hand 
or  arm,  63 

-  and  language  (symbolic,  picto- 
graphic,  syllabic),  232 


UNCONSCIOUS,  the,  and.subcortical   auto- 
matisms, 13,  317 


ZONE.     (See  Area  and  Centre) 


INDEX  OF  AUTHORS 


ADLER,  396 
Andrizen,  333 
Anton,  200 
Aristotle,  244 
Aschaffenburg,  220,  224 
Azam,  318 

B 

BABINSKI,  36 

Bacon,  254 

Bain,  210,  221 

Baldwin,  253,  292,  293,  298 

Ballet,  235,  322 

Basedow,  295 

Bastian,  235,  238 

Baum,  98 

Bechterew,  8,   75,  84,   92,   126,   188,    191, 

192,  194,  264,  265,  266,  267 
Beduschi,  32 
Beethoven,  331 
Beevor,  105,  189,  199 
Belfiore,  318 
Benedicenti,  261 
Bergson,  212,  282 
Bergstrom,  223 
Bernard,  235,  261 
Bernheim,  318 
Bessau,  193 
Betz,  117 

Beyermann,  84,  265 
Bianchi,  L.,  13,  22,  36,  54,  57,  63,  76,  83, 

87,  92,  126,  188,  190,  191,  203,  222,  241, 

254,  263,  288,  300,  318,  325 
Bianchi,  V.,  15,  96,  107,  127,  157 
Binet,  224,  318 
Bleuler,  318 
Boccardo,  292 
Bochefontaine,    84,    264,    265,    266,    267, 

268 

Bohn,  7,  8,  59,  129,  130,  328 
Bolton,  25,  61,  113,  114,  116 
Bonne,  117 
Bourbousson,  261 
Bourdon,  220 
Bourgeois,  318 
Braunstein,  193 
Brehm,  289,  307 
Brissot,  244 
Broadbent,  235 
Broca,  69,  83,  97,  108 
Brodmann,  25,  33,  61,  62,  105,  110,  111, 

113,  114,  117,  118 
Bruno,  221,  284 
Bunke,  194 
Burdach,  50,  68 
Byron,  213 


C 


CAJAL,  203,  320 
Calkins,  220,  272 

345 


Calvin,  284 

Campbell,    25,    33,  61,  62,  105,  109,  110 

111,112,113,  114,117 
Canalis,  261 
Cantani,  126 
Cantoni,  3 
Cathcart,  328    . 
Cerevkov,  266 
Charcot,  51,  61,  235,  238 
Chopin,  331 
Cleofante  Corintio,  230 
Cole,  107 
Comte,  294,  328 


D 


DANILEWSKI,  264,  266 

Dante,  237 

Dantec,  8 

Darwin,  253 

David,  230 

Dearborn,  224,  279 

Deboyer,  61,  62 

De  Brosses,  227 

Dejerine,  29,  61,  114,  127,  198,  199,  200, 

201,  202,  207,  242 
Delaroche,  261 
De  Molinari,  293 
Di  Sanctis,  S.,  221 
De  Sarlo,  314 
Dewey,  13 
Donaggio,  320 
D'Ors,  254 
Drzewina,  7 

Du  Bois-Reymond,  3,  136,  160 
Dumas,  221 
Dupre,  242 
Dwelshauvers,  317 


EBERSTALLER,  97 
Eckard,  266 
Ecker,  211 

Edinger,  9,  11,  95,  201 
Ellenberger,  98 
Engelmann,  6 
Espinas,  318 
Euripides,  230 
Exner,  311 


FANO,  86,  324 

Fere,  271,  273 

Ferrari,  279 

Ferreri,  235 

Ferri,  261 

Ferrier,  17,  31,  50,  51,  70,  71,  74,  75,  76, 

92,  96,  132,  187,  189,  191 
Ferrier  et  Yeo,  31 


346 


INDEX  OF  AUTHORS 


Flechsig,  21,  22,  25,  26,  27,  28,  29,  30,  31, 
32,  47,  48,  58,  59,  61,  64,  67,  68,  76,  78, 
79,  81,  82,  83,  91,  92,  107,  109,  114,  202, 
240,  241,  268,  270 

Fleurens,  68,  73 

Forel,  7,  199 

Fragnito,  320 

Franceschi,  52 

Fran9ois  Frank,  84,  265,  267 

Franck,  192 

Freud,  222,  225,  317,  318,  320 

Fubini,  261 

Funke,  271 


G 


GALL,  68 

Gamier,  130,  289 

Gehuchten  v.,  320 

Geiger,  332 

Gerver,  268 

Giannelli,  265 

Gilmann,  271 

Golgi,  320 

Goltz,  14,  69,  74,  75,  76,  77,  88,  92,  128 

Gratiolet,  69 

Grimm,  285 

Grossglick,  75,  92,  132 

Grunbaum,  62,  71,  189 

Grtinhagen,  193 


H 


HAAB,  194 

Hammerburg,  117 

Havet,  5 

Helmoltz,  1 

Henrick,  12 

Henry,  224 

Henschen,  23 

Herrick,  14 

Herring,  324 

Herrmann,  271 

Hertwig,  O.  and  K.,  5 

Hertz,  3 

Hitzig,    16,    20,  21,  22,  29,  31,  50,  59,  69, 

70,  73,  74,  76,  81,  92,  130,  132,  187,  196 
Hobhouse,  307,  312 
Horsley,  18,  31,  78,  79,  92,  105,  123,  132, 

188,  265 
Hufeland,  67 
Hughlings,  Jackson,  119 
Hunter,  260 


INGENIEBOS,  130,  215 
Ireland,  68 


JACOB,  9,  94,  107,  117 

James,  80,  211,  223,  274,  276,  279,  290 

Jennings,  l.'JO 

Johnston,  11,  307 

Jones,  317 

Jung,  318 


K 

KALISCHER,  79,  127 
Kennedy,  58 
Kinnamann,  130 
Kirchhoff,  270 
Kleinenberg,  5 
Kocher,  63 
Kolliker,  203 
Kulpe,  272 
Kussmaul,  34,  51,  235 


LAMARCK,  8 

Lancisi,  68 

Lange,  273,  276,  278,  280 

Langelaan,  84,  85,  265 

Langley,  279 

Lehmann,  273 

Leibnitz,  227 

Lelut,  69,  222 

Lemesle,  223 

Lepine,  264,  268 

Le  Play,  295 

Leuret,  97 

Levinsohn,  188 

Levy  Bruhle,  293 

Libertini,  85,  324 

Lichstein,  235 

Linder,  298 

Loeb,  3,  7,  9,  15,  78,  303,  305,  324 

Lombroso,  Cesare,  261,  276 

Lombroso,  Paolo,  231 

Lorenz,  3 

Loria,  293 

Lubbock,  7 

Luciani,  12,  31,  50,  51,  75,  78,  79,  84,  107, 

132,  187 
Lugaro,  91,  307,  320,  322,  326 


M 


McCABE,  303,  305,  312 

Macci,  212 

Mallet,  322 

Malloizel,  268 

Mantegazza,  278 

Maragliano,  126 

Marchand,  105 

Marie,  24,  50,  63,  195,  244 

Marinesco,  203 

Marshall,  272 

Marx,  293 

Maschka,  288 

Massarotti,  261 

Matteucci,  3 

Maxwell,  3 

Mead,  271 

Meyer,  298 

Meynert,  81,  97,  108,  203,  271,  333 

Mezes,  272 

Michelangelo,  213 

Michtovte,  328 

Miller,  271 

Mills,  119 

Mingazzini,  242,  244 

Mirallie,  61 


INDEX  OF  AUTHORS 


347 


Mislawski,  84,  188,  266,  267,  268 

Moleschott,  261 

Monakow,  29,  32,  35,  87,  90,  91,  92,  98, 

121,  122,  199,  200,  207,  333 
Montesquieu,  261 
Montier,  244 
Moolmann,  77 
Morelli,  223 

Morgan,  303,  306,  307,  312 
Moriceau,  201 
Morpurgo,  261 

Morselli,  214,  261,  302,  317,  318 
Mosso,  84,  213,  262,  267,  276 
Mott,  62,  109,  110,  189 
Miiller,  227,  228,  229 
Munk,  20,  24,  31,  69,  70,  74,  75,  76,  78,  81, 

82,  84,  86,  92,  97,  128,  129,  132,  196,  264 
Mtinsterberg,  279 
Muratow,  200 
Myers,  322,  323 


N 


NEGRINI,  98 
Nero,  230 
Nikitin,  268 
Nordau,  298 
Novikow,  293 


ODDI,  86,  324 
Onufrowicz,  199 
Orbeli,  328 
Orestano,  313 
Ostankow,  267 


PARKER,  6 
Patrizi,  213,  276 
Paulham,  221 
Pavlov,  128,  268,  328 
Pearson,  188 
Pellacani,  84,  267,  289 
Penta,  76,  261 
Pergolesi,  331 
Pfeffer,  7 
Pfungen,  84 
Phelps,  119 
Pieret,  7 
Pilcz,  194 

Pitres,  61,  62,  84,  192 
Plato,  227 

Polimanti,  78,  86,  87, 
Potter,  97 
Pouchet,  6 
Power,  303 
Preyer,  307,  310 
Prince,  317,  322 
Probazenski,  265 


QUENSEL,  202 


RADL,  8 

Ramon  y  Cajal,  203,  320 


Regnaud,  282 

Rehmka,  278 

Renan,  227 

Ribot,  211,  271,  272,  278 

Richet,  272 

Righi,  1,  3 

Rignano,  211 

Robertson,  229 

Romanes,  243,  298,  307,  310 

Roncoroni,  89,  90,  118,  127 

Rontgen,  3 

Rossini,  331 

Rossolimo,  92 

Rutishauser,  92 


SACHS,  203 

Saint-Simon,  294 

St  Francis  d'Assisi,  284 

St  Catherine  of  Siena,  284 

Schafer,  78,  79,  92, 117,  124,  132,  188,  189, 

293 

Schiff,  87,  266 
Schnopfhagen,  199 
Schopenhauer,  283 
Schrader,  14,  15 
Schukowski,  202 
Schuster,  62,  110 

Sciamanna,  79,  83,  84,  85,  126,  133,  298 
Seglas,  242,  244 
Semon,  265,  305 
Senise,  278 
Sergi,  G.,  298 
Sergi,  S.,  83,  118,  119 
Shakespeare,  229 
Shepherd,   I.,  75,  88,  89,    119,   124,    125, 

126,  130 
Sherrington,  62,  71,  84,  110,  123,  189,  323, 

324 

Sidis,  318,  319,  321 
Sidney,  272 
Siemerling,  29 
Smith,  84 
Socrates,  222 
Sollier,  240,  268 
Soury,  50 

Spencer,  84,  253,  272,  293,  294 
Spindler,  279 
Spinoza,  283 
Spurzhein,  67,  68 
Starr,  17,  119 
Stewart,  188 
Stratton,  277 
Strieker,  238 
Subbock,  128 
Sydenham,  278 
Sydney-Cole,  107 
Sikorsky,   279 


TAINE,  231 

Tamburini,  31,  50,  51,  83,  187,  322 

Tanzi,  322,  326 

Tarde,  294,  298 

Tenchini,  98 

Thorndike,  88,  129,  130,  289,  312 

Thornton,  7 

Tomasini,  266 


348  INDEX  OF  AUTHORS 

Topolanski,  324  Wassiliew,  328 

Turner,  105,  113  Watson,  113,  117 

Waxweiler,  291 
U  Webster,  229 

Werner,  75 
UNVEKRICHT,  75,  76  Wernicke,  34,  51 

Westphall,  195 

Wilson,  287 
V  Winkler,  97 

Worms,  293 

VAN  GEHUCHTEN,  198,  199  Wundt,  80,  83,  193,  219,  220,  224,    254, 

Vascide,  223  271,  272 

Verdi,  331 
Verworn,  305 
Vialet,  23 

Vogt,  29,  117,  118  Z 

Voltaire,  233 

Vulpain,  267  ZELIONY,  128 

W  Zell,  307 

Zimmerl,  99 

WAKD,  271  Zingerle,  200 

Wasmann,  7  Zulowski,  93 


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